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Modern criminal investigations heavily rely on trace bodily fluid evidence as a rich source of DNA. DNA profiling of such evidence can result in the identification of an individual if a matching DNA profile is available. Alternatively, phenotypic profiling based on the analysis of body fluid traces can significantly narrow down the pool of suspects in a criminal investigation. Urine stain is a frequently encountered specimen at the scene of crime. Raman spectroscopy offers great potential as a universal confirmatory method for the identification of all main body fluids, including urine. In this proof-of-concept study, Raman spectroscopy combined with advanced statistics was used for race differentiation based on the analysis of urine stains. Specifically, a Random Forest (RF) model was built, which allowed for differentiating Caucasian (CA) and African American (AA) descent donors with 90% accuracy based on Raman spectra of dried urine samples. Raman spectra were collected from samples of 28 donors varying in age and sex. This novel technology offers great potential as a universal forensic tool for phenotypic profiling of a potential suspect immediately at the scene of a crime, providing invaluable information for a criminal investigation. [ABSTRACT FROM AUTHOR]

Biological fluid stains can be instrumental in solving crimes. Identification of semen can help reconstruct events in sexual assault cases and identify suspects via DNA profiling. Current methods for semen identification suffer from limitations, including destruction of the sample and potential false positives. One of the main unsolved issues is the elimination of underlying substrate interference. In this paper, chemometric approaches were developed to isolate and identify a biofluid stain on interfering substrates using Raman spectroscopy. The first approach, called Multivariate Curve Resolution with the Addition Method, combines the standard addition method with multivariate curve resolution. The second one uses a criterion based on reducing the spectrum complexity when a spectral component is removed from a Raman spectrum of a multi-component sample entirely. The results demonstrate the superiority of the first approach relative to the second for both small volume fraction of the fluid stain compared to the substrate and random noise. [ABSTRACT FROM AUTHOR]

This preliminary research aimed to determine if a forensically useful human DNA profile could be obtained from latent blood past the point at which the blood could be visualized with luminol. Five participants with differing physical characteristics created shoeprints from fresh human blood over concrete, linoleum and carpet. The amount and distribution of both visible blood and chemiluminescence emanating from latent blood were documented. DNA analysis was performed on samples taken from the fifth last latent shoeprint to show chemiluminescence and the first and tenth steps after which chemiluminescence no longer occurred. DNA from the blood source was obtained past the point of visualization using luminol, with 2 of the 30 samples generating full STR DNA profiles, 18 generating partial profiles of 4 or more alleles, and 3 generating between 1 and 3 alleles. Of the 7 samples which did not generate a profile, 6 came from the concrete. Higher amounts of DNA, and more full and partial profiles, were obtained from linoleum compared to concrete or carpet. Participant effect was not observed. These findings demonstrate that it may be possible to obtain forensically useful DNA from crime scenes even when blood is not able to be visualized with chemiluminescence. [ABSTRACT FROM AUTHOR]

Bite mark analysis plays a pivotal role in forensic investigations, by helping to identify suspects and establish links between individuals and crime scenes. However, traditional bite mark methodologies face significant challenges due to issues with reliability and subjectivity. Recent advances in microbiome analysis, which involves identifying and characterizing the microbial communities found in bite marks, have led to the emergence of a promising tool for forensic investigations. The integration of microbiome analysis with conventional DNA profiling enables more accurate interpretation of bite mark evidence in forensic investigations. This review provides an in-depth look at the integration of bite mark microbiome analysis with forensic DNA profiling. It also addresses the challenges and strategies involved in microbiome-based bite mark analysis for forensic purposes. [ABSTRACT FROM AUTHOR]

At many crime scenes, investigators are able to trace and find traces of blood. For many years, it was believed that such traces could only be subjected to genetic investigations, such as those aimed at comparing DNA profiling with a suspect to verify his identity, and that it was therefore not possible to backdate the traces. In recent years, various works have used experimental models to investigate the possibility of identifying markers and methodologies for estimating the time since deposition (TSD) of bloodstains. Despite the results, these methods are still not part of standard procedures, and there is no univocal analysis methodology. In this work we carried out a systematic literature review of all the papers published in the last ten years on this topic, comparing the experimental models created. This review demonstrates the potential that different molecular approaches, such as transcriptomics, metabolomics, proteomics, and spectrometry, can have in the analysis of TSD, with notable sensitivity and specificity. This paper also analyzes the intrinsic and extrinsic limits of these models and emphasizes the need to continue research work on this topic, considering the importance that this parameter can assume in forensic investigations against a suspect. [ABSTRACT FROM AUTHOR]

DNA technology is the gold standard with respect to the identification of individuals from biological evidence. The technology offers the convenience of a universally similar approach and methodology for analysis across the globe. However, the technology has not realised its full potential in India due to the lack of a DNA database and lacunae in sample collection and preservation from the scene of crime and victims (especially those of sexual assault). Further, statistical interpretation of DNA results is non-existent in the majority of cases. Though the latest technologies and developments in the field of DNA analysis are being adopted and implemented, very little has been enacted practically to improve optimise sample collection and preservation. This article discusses current casework scenarios that highlight the pitfalls and ambiguous areas in the field of DNA analysis, especially with respect DNA databases, sampling, and statistical approaches to genetic data analysis. Possible solutions and mitigation measures are suggested. [ABSTRACT FROM AUTHOR]

Commercial panels of microsatellite (STR) loci are focused on the use of DNA of the domestic dog (Canis lupus familiaris) and are often inapplicable for genotyping the DNA of the gray wolf (Canis lupus lupus). We propose a CPlex test system, including one hexa‐ and 12 tetranucleotide autosomal STR loci, as well as two sex loci, that is equally efficient in DNA identification of biological samples of the wolf and the dog. Analysis of molecular variance between samples revealed significant differentiation values (FST = 0.0784, p < 0.001), which allows to use the panel to differentiate wolf and dog samples. Population subdivision coefficients (θ‐values) were calculated for each of the 13 STR loci of the developed test system. It was shown that the values of the genotype frequency for dogs and wolves, without and with considering the θ‐value, differ by three orders of magnitude (for dogs 8.9 × 10−16 and 2.1 × 10−14 and for wolves 1.9 × 10−15 and 4.5 × 10−14, respectively). The use of population subdivision coefficients will allow to identify the most reliable results of an expert identification study and the power of exclusion provided by the STR loci of the CPlex test system makes it possible to achieve a reliable level of evidence in forensic DNA analysis of both wolves and dogs. The test system has been validated for use in forensic identification of the dog and wolf based on biological traces found at crime scenes, as well as for individual identification and establishing biological relationship of animals of these species. [ABSTRACT FROM AUTHOR]

Body fluid identification is fundamental in forensic science as it links a specific biological source to a genetic profile, thus providing critical clues for crime scene reconstruction. Blood is one of the most common body fluids found on the crime scene, and several strategies have been developed for its identification in recent decades. Usually, after a preliminary (or presumptive) test to determine the presence of blood (both human and non-human), a confirmatory test is needed to prove that the sample is human blood. Out of the confirmatory tests, immunochromatographic (IC) assays are the most commonly and widely used. This work gives a review of the use of commercial kits specifically developed to detect human hemoglobin or glycophorin A (a surface protein of human red cells) in forensics. Claimed sensitivity varies broadly (ranging from 0.06 to 75 nanoliters of fresh blood), but different values (as low as 0.002 nL) were found during validation procedures. Specificities are high, and the possibility of cross-reaction (with the risk of false-positive results) is so low that it can be considered negligible. False-negative results, however, can be found due to the so-called "hook effect" as well as to the target degradation/modification, which interferes with the Ag-Ab binding. In addition, the chemical compositions of the presumptive test, detergents, and washing can also promote false negative outcomes in peculiar situations. Although IC assays are rapid, inexpensive, specific, and easy to use even on the crime scene, their major limitation is represented by the destructive approach required by this kind of confirmatory test. Since the final goal of the forensic investigation is the genetic typing of a bloodstain, we will describe the strategies developed for IC assays of faint stains as well as the strategies adopted to ensure that exactly the same sample undergoes human blood identification and DNA typing. [ABSTRACT FROM AUTHOR]

Selecting the optimal sampling method is an essential component of the DNA analysis process. Errors or omissions in targeting and gathering relevant samples can significantly reduce the likelihood of obtaining a valuable DNA profile, affecting the profile's quality and evidential value and ultimately hindering its ability to support the justice system. While DNA typing techniques have become significantly more sensitive in recent years, there is an ongoing need for further advancements in the recovery of DNA from crime scenes. It is essential to improve the accuracy and reliability of forensic investigations, particularly in cases where only tiny amounts of DNA are present, such as touch DNA samples or degraded forensic evidence. Parameters, including swab material, type of substrate, and swabbing protocol, that influence the efficiency of a swab are discussed in this review. This is followed by a literature review of studies that have compared swab types and/or other sampling conditions. While swabs are the most-used collection tools at a crime scene, alternatives are available. These alternatives are reviewed, including their advantages and disadvantages. A critical discussion and conclusions make clear that, unfortunately, neither swabs nor their alternatives are highly effective in recovering DNA from a substrate. [ABSTRACT FROM AUTHOR]

Blood is one of the most commonly found biological fluids at crime scenes, with the detection and identification of blood holding a high degree of evidential value. It can provide not only information about the nature of the crime but can also lead to identification via DNA profiling. Presumptive tests for blood are usually sensitive but not specific, so small amounts of the substrate can be detected, but false-positive results are often encountered, which can be misleading. Novel methods for the detection of red blood cells based on aptamer–target interactions may be able to overcome these issues. Aptamers are single-stranded DNA or RNA sequences capable of undergoing selective antigen association due to three-dimensional structure formation. The use of aptamers as a target-specific moiety poses several advantages and has the potential to replace antibodies within immunoassays. Aptamers are cheaper to produce, display no batch-to-batch variation and can allow for a wide range of chemical modifications. They can help limit cross-reactivity, which is a hindrance to current forensic testing methods. Within this study, a modified Systematic Evolution of Ligands by Exponential Enrichment (SELEX) process was used to generate aptamers against whole red blood cells. Obtained aptamer pools were analysed via massively parallel sequencing to identify viable sequences that demonstrate a high affinity for the target. Using bioinformatics platforms, aptamer candidates were identified via their enrichment profiles. Binding characterisation was also conducted on two selected aptamer candidates via fluorescent microscopy and qPCR to visualise and quantify aptamer binding. The potential for these aptamers is broad as they can be utilised within a range of bioassays for not only forensic applications but also other analytical science and medical applications. Potential future work includes the incorporation of developed aptamers into a biosensing platform that can be used at crime scenes for the real-time detection of human blood. [ABSTRACT FROM AUTHOR]

Generating degraded DNA samples can be useful for forensic DNA research as this can mimic the condition of crime scene samples and results from such samples. Methods which use quick and cost-effective ultraviolet light (UV) exposure can be utilized to degrade DNA but are not well documented. This study aimed to establish a procedure and define the parameters required to generate Short Tandem Repeat (STR) profiles at different degradation levels. UV exposure times between 0 and 60 s were tested using genomic and control DNA. Sample eluates were quantified with QuantifilerTM Trio pre- and post-UV exposure, and select samples were profiled using PowerPlex® 21. Quantification data and STR profiles were analysed to identify metrics which indicated degradation severity. Samples were observed to be degraded by UV exposure as evidenced by established DNA degradation markers. No specific metric was identified to reliably determine the severity of sample degradation, but it was noted that UV exposure between 5 and 10 s resulted in mild degradation, between 15 and 25 s generated moderate degradation, and between 45 and 60 s resulted in severe degradation in STR profiles. This study indicates that quantification before and after UV exposure may be useful to estimate the degree of degradation via one quantification target. [ABSTRACT FROM AUTHOR]

At a crime scene, investigators are faced with a multitude of traces. Among them, biological traces are of primary interest for the rapid genetic-based identification of individuals. "Touch DNA" consists of invisible biological traces left by the simple contact of a person's skin with objects. To date, these traces remain undetectable with the current methods available in the field. This study proposes a proof-of-concept for the original detection of touch DNA by targeting cell-derived fragments in addition to DNA. More specifically, adhesive-structure proteins (laminin, keratin) as well as carbohydrate patterns (mannose, galactose) have been detected with keratinocyte cells derived from a skin and fingermark touch-DNA model over two months in outdoor conditions. Better still, this combinatory detection strategy is compatible with DNA profiling. This proof-of-concept work paves the way for the optimization of tools that can detect touch DNA, which remains a real challenge in helping investigators and the delivery of justice. [ABSTRACT FROM AUTHOR]

Already for some decades lateral flow assays (LFAs) are 'common use' devices in our daily life. Also, for forensic use LFAs are developed, such as for the analysis of illicit drugs and DNA, but also for the detection of explosives and body fluid identification. Despite their advantages, including ease-of-use, LFAs are not yet frequently applied at a crime scene. This review describes (academic) developments of LFAs for forensic applications, focusing on biological and chemical applications, whereby the main advantages and disadvantages of LFAs for the different forensic applications are summarized. Additionally, a critical review is provided, discussing why LFAs are not frequently applied within the forensic field and highlighting the steps that are needed to bring LFAs to the forensic market. [ABSTRACT FROM AUTHOR]

Despite the advent of DNA profiling, fingerprints still play an important role in suspect identification. However, if single crime scene marks may be challenging to identify, overlapping fingermarks, understandably, pose an even greater challenge. In the last decade, mass spectrometry-imaging methods have provided a possible solution to the separation of fingermarks from two or more donors, based on the differential chemical composition. However, there are no studies attempting to separate overlapping marks from the same donor. This is important in relation to fingermark deposition at different times, which could be critical, for example, to ascertain legitimate access to the scene. In the work presented here, we investigate whether Matrix-Assisted Laser Desorption Ionisation Mass Spectrometry Imaging can separate the same donor's fingermarks deposited at different times based on intra-donor fingermark composition variability. Additionally, the hypothesis that the different times of deposition could be also determined was investigated in the view of linking the suspect at the scene at different times; the dating window of MALDI MSI within the selected molecular range was explored. Results show that it is possible to separate overlapping fingermarks from the same donor in most cases, even from natural marks. Fresh marks (0 days) could be separated from those of fourteen days of age, though the latter could not be distinguished from the set aged for seven days. Due to the use of only one donor, these are to be considered preliminary data, though findings are interesting enough to warrant further investigation of the capabilities and limitations of this approach using a larger cohort of donors. [ABSTRACT FROM AUTHOR]

This systematic review describes and discusses three commercially available integrated systems for forensic DNA analysis, i.e., ParaDNA, RapidHIT, and ANDE. A variety of aspects, such as performance, time-to-result, ease-of-use, portability, and costs (per analysis run) of these three (modified) rapid DNA analysis systems, are considered. Despite their advantages and developmental progress, major steps still have to be made before rapid systems can be broadly applied at crime scenes for full DNA profiling. Aspects in particular that need (further) improvement are portability, performance, the possibility to analyze a (wider) variety of (complex) forensic samples, and (cartridge) costs. Moreover, steps forward regarding ease-of-use and time-to-result will benefit the broader use of commercial rapid DNA systems. In fact, it would be a profit if rapid DNA systems could be used for full DNA profile generation as well as indicative analyses that can give direction to forensic investigators which will speed up investigations. [ABSTRACT FROM AUTHOR]

Mob lynching is the heinous crime in the world by which a group of people kills the criminal or suspects of crime. In 2018 forensic science team facing the challenge of such horrible crime. Forensic Science Laboratory received a mass number of exhibits and analysis of this large number of exhibits was critical, complex and timeconsuming. Analysis of crime scene evidences recovered from suspects and biological samples of deceased along with their clothes were performed. Step by step analysis of these exhibits carried out by the detection of blood which minimizes the complexity of analysis and DNA profiling of these blood detected exhibits decreases the time cycle and increases the truthiness of analysis. DNA profiles obtained from a mass number of crime scene evidence and evidence recovered from suspects linked with DNA profiles of the deceased. This concludes the crime of mob lynching, uniqueness of the location and presence of a suspect at that time with the same location. [ABSTRACT FROM AUTHOR]

The sensitivity and discrimination power of modern DNA profiling systems means that very small amounts of DNA from an individual can be detected on an item leading to large inclusionary statistics for that person. The sensitivity of these systems has significant benefits in the investigation of crime but also can be highly sensitive to contamination of exhibits or crime scenes. It becomes critical to distinguish between deposition during commission of a crime or deposition via some other method unrelated to the crime. This study investigates methodologies used in crime scene examination and the potential for them to cause non-crime-related transfer of DNA. Factors assessed include the source of DNA, the handling time, the amount of movement during contact, and the substrate type. The amount of movement and the number of transfer steps are the most critical in determining whether, and how much, DNA is transferred. This study provides information for crime scene examiners and also scientists assessing transfer scenarios. [ABSTRACT FROM AUTHOR]

• Biological traces are widely present in forensic casework. • Current examination methods provide limited information about the trace. • A historical review of the forensic examination of biological traces can help understand how research is addressing these limitations. • Novel techniques may unlock previously unknown information from these traces. Forensic investigation involves gathering the information necessary to understand the criminal events as well as linking objects or individuals to an item, location or other individual(s) for investigative purposes. For years techniques such as presumptive chemical tests, DNA profiling or fingermark analysis have been of great value to this process. However, these techniques have their limitations, whether it is a lack of confidence in the results obtained due to cross-reactivity, subjectivity and low sensitivity; or because they are dependent on holding reference samples in a pre-existing database. There is currently a need to devise new ways to gather as much information as possible from a single trace, particularly from biological traces commonly encountered in forensic casework. This review outlines the most recent advancements in the forensic analysis of biological fluids, fingermarks and hair. Special emphasis is placed on analytical methods that can expand the information obtained from the trace beyond what is achieved in the usual practices. Special attention is paid to those methods that accurately determine the nature of the sample, as well as how long it has been at the crime scene, along with individualising information regarding the donor source of the trace. [ABSTRACT FROM AUTHOR]

This qualitative exploratory study closely look at the evidential value of carcass traces in combating stock theft in South Africa. It was confined to the selected areas of KwaZulu-Natal (KZN) Province of South Africa. The Deoxyribonucleic Acid (DNA) technology, DNA testing, DNA profiling or Genetic fingerprinting refers to a technique adopted to identify and distinguish livestock by their DNA samples, focusing on patterns uniqueness of DNA sources (Carcass, fingerprints, footprints, hair, skin cells, blood, bodily fluids, pieces of clothing and fibres, alike). About 49 participants were purposively sampled, all from the KZN Province. The data was collected through Key Informant Interviews (KII) and Focus Group Discussions (FGDs). The inductive thematic methods was employed for data analysis. This study established that crime scenes involving livestock should be investigated using the same principles as any other crime scenes. It is also confirmed that every time contact is made with another person, place, or object, it results in an exchange of physical materials, carcass includes. Summarily, no matter where a stock thieve criminal go or do, by coming into contact with carcass, they can leave evidence behind, including the mentioned various DNA sources, which could positively lead to the scientific reconstruction of events, interpretation of observations and measurements from the stock theft scenes to collect physical evidence. For recommendations, the Anti-Stock theft structures should avoid mistakes in the recovering of stock theft scenes, sample collections or test procedures. They should ensure that the results are accurate by following all procedural measures, lay down guidelines for maintaining the chain of custody to ensure that the DNA tests become conclusive, and they should further provide detailed information about discovered carcass, while placing more emphasis on this type of evidence. [ABSTRACT FROM AUTHOR]

• Highly probative contributor STR genotype information recovered from complex mixtures by direct single cell subsampling (DSCS) and probabilistic genotyping (PG) with replicate analysis. • STRmix™ was validated for use with single cells. • Replicate analysis of single cells often allows for full STR genotype information recovery comparable to reference profiles. • DSCS reduces genotype information loss seen in standard mixture analysis. DNA mixtures are a common source of crime scene evidence and are often one of the more difficult sources of biological evidence to interpret. With the implementation of probabilistic genotyping (PG), mixture analysis has been revolutionized allowing previously unresolvable mixed profiles to be analyzed and probative genotype information from contributors to be recovered. However, due to allele overlap, artifacts, or low-level minor contributors, genotype information loss inevitably occurs. In order to reduce the potential loss of significant DNA information from donors in complex mixtures, an alternative approach is to physically separate individual cells from mixtures prior to performing DNA typing thus obtaining single source profiles from contributors. In the present work, a simplified micro-manipulation technique combined with enhanced single-cell DNA typing was used to collect one or few cells, referred to as direct single-cell subsampling (DSCS). Using this approach, single and 2-cell subsamples were collected from 2 to 6 person mixtures. Single-cell subsamples resulted in single source DNA profiles while the 2-cell subsamples returned either single source DNA profiles or new mini-mixtures that are less complex than the original mixture due to the presence of fewer contributors. PG (STRmix™) was implemented, after appropriate validation, to analyze the original bulk mixtures, single source cell subsamples, and the 2-cell mini mixture subsamples from the original 2–6-person mixtures. PG further allowed replicate analysis to be employed which, in many instances, resulted in a significant gain of genotype information such that the returned donor likelihood ratios (LRs) were comparable to that seen in their single source reference profiles (i.e., the reciprocal of their random match probabilities). In every mixture, the DSCS approach gave improved results for each donor compared to standard bulk mixture analysis. With the 5- and 6- person complex mixtures, DSCS recovered highly probative LRs (≥1020) from donors that had returned non-probative LRs (<103) by standard methods. [ABSTRACT FROM AUTHOR]

• Blood recovered from snow can yield viable DNA profiles suitable for court. • Various substrates commonly used by Forensic Identification Officers are sufficient mediums for recovering high yield blood from snow, where replicates performed consistently. • Slight variability in DNA yields and genotyping performance across the three substrates was observed, attributable to differences in methodology/evidence collection. Successful DNA typing of forensically relevant evidence is reliant on both the quality and quantity of biological material recovered from a crime scene. In geographical areas of the world exposed to cold climates, it is not uncommon for biological evidence to encounter a diversity of challenging surfaces and environments, including snowy surfaces. Currently, there is no standard protocol for recovery of bloodstain evidence in snow and very few publications exploring adequate methods of recovering biological evidence from snowy surfaces. In this study, three common substrates (e.g., cotton swabs, FTA paper, and untreated filter paper) utilized by investigators for evidence recovery were evaluated for their ability to recover human blood (DNA) evidence from snow that would be viable for traditional forensic DNA typing. Each biological sample was extracted and quantified to evaluate the quality and quantity of DNA recovered. All samples yielded sufficient non-degraded DNA to proceed with DNA profiling, where complete DNA profiles were generated from each collection substrate. The experimental findings presented herein demonstrate that the ability to recover viable DNA from human blood collected on surface snow is possible using all three collection methods tested. [ABSTRACT FROM AUTHOR]

Increasingly in courts, the source of forensic DNA trace evidence is not challenged by the defence. Instead, the issue relates to how the suspect's DNA got to the crime scene, suggesting it arrived via a legitimate activity. Many burglaries are committed using a new lock-picking method called 'foil impressioning', which involves inserting aluminium foil into the lock. When DNA is recovered from this foil, suspects will say that they only cut the foil and sell or discard it, to be used later in lock-picking by someone else. This study elucidates the probabilities of recovering DNA profiles from aluminium foil in three situations: (1) when a person only cuts the foil, (2) when they cut and then use it for lock-picking and (3) when they cut it and someone else uses it for lock-picking. Using a Bayesian network, we conclude that the probability of recovering a person's DNA profile from foil inside a picked lock is seven times higher if they picked the lock than if they only cut the foil. This study demonstrates how likelihood ratios based on probabilistic models of DNA transfer and persistence can now help the court address questions about the mode of deposition of DNA traces. [ABSTRACT FROM AUTHOR]

• Providing a newly exploited trace DNA extraction platform based on magnetic bead-based method. • Establishing an automatic and efficient detection system for trace DNA. • The fingerprint materials were successfully dissected in the self-developed automatic detection system. The analysis of trace DNA is a crucial component in forensic applications. Biological materials containing low-level DNA collected at crime scenes, such as fingerprints, can be valuable as evidence. Automatic detection of biological samples has been largely embraced in forensic applications to meet the increasing throughput requirements. However, the amount of DNA automatically retrieved from trace evidence often tends to be small and unstable, ultimately resulting in poor detection of DNA profiles. Thus, in this work, we introduced a robust DNA extraction and purification platform named Bionewtech® BN3200 (Bionewtech®, Shanghai, China) with the goal of constructing a rapid automatic detection system for trace DNA. The establishment of automatic detection system for trace DNA mainly encompassed two parts: assessing the sensitivity of automatic extraction platform and screening the optimal short tandem repeat (STR) typing kit. The sensitivity of Bionewtech® BN3200 platform based on Ultra-sensitive DNA Extraction kit was initially estimated, demonstrating that this extraction platform might contain large potential in the trace DNA extraction. For the amplification part, three sets of commercial multiplex STR typing kits were selected as candidates, and the amplified products were further genotyped on the Applied Biosystems 3500xl Genetic Analyzer. After comparation, SiFa™ 23 Plex Kit was determined as the most suitable amplification system for trace DNA. Eventually, the newly exploited trace DNA detection system was successfully implemented in the detection of fingerprints derived from glass surfaces with the five-seconds contact time. As a result, the DNA recovered from the fingerprints fluctuated approximately from 57.60 pg to 18.05 ng, in addition, over 70% of the total STR loci were detected in 75% of the fingerprint samples. [ABSTRACT FROM AUTHOR]

Fired cartridge cases are common materials found at crime scenes and, for the most part, are used for Forensic Ballistics analysis. We aimed to evaluate the feasibility of recovering DNA profiles from 9 mm cartridge cases over 30 days. Therefore, 27 fired cartridge cases were manipulated by three volunteers in total and analyzed after three-time intervals: 3, 8, and 30 days. Volunteers were asked to handle the ammunition as they would daily. However, they were not encouraged to hold and manipulate the ammunitions extensively, as this procedure does not represent a real-life situation. DNA samples were obtained with an EZ1 DNA Investigator kit, qPCR was performed with Investigator Quantiplex Pro RGQ kit, and Powerplex Fusion 6 C was used for STR analysis. Real-time PCR analysis showed that 85% of the 27 samples were degraded and no inhibition was detected. The DNA mean concentration was 0.3 pg/µl for each time interval, and the standard error was 0.1 pg/µl, 0.09 pg/µl, and 0.1 pg/µl for the three-time corresponding intervals. The Kruskal-Wallis test indicated p = 0.6, which meant no statistical differences between the samples analyzed. STR analysis resulted in a success rate of 16% for intervals of 8-days and a success rate overall of 7%. No DNA profile was obtained from the 3-and 30-day-old samples. Air relative humidity was 75% on the day of experimentation. Our results could contribute to understanding the factors affecting genetic profiles from fired cartridge cases: 3-day-old samples already showed 77.8% degradation. Once moisture catalyzes the metal oxidation processes, relative humidity and the metallic surface of cartridges may play an important role. We assume that time interval may not be the main factor regarding DNA analysis success, and low success rates are more likely to be obtained for real-life scenarios. [ABSTRACT FROM AUTHOR]

Items from crime scenes are frequently packaged and transported to laboratories for forensic examination. The packaging primarily maintains the integrity of forensic evidence associated with the item by protecting it from contamination and environmental impacts, plus limiting and recording access. There is diversity in the types of packaging used. We are aware that DNA-containing material may transfer from an item to the internal side of packaging and/or from one area of an item to another area, potentially limiting generation of good quality DNA profiles and/or affecting their interpretation. However, the level of transfer risk is unclear, as are the main impacting factors. It is thus highly relevant to improve our understanding of these. Here we explore what commonly applied standards prescribe regarding packaging requirements to maintain the integrity of DNA on a packaged item, conduct further studies confirming the risk of transfer, and suggest packaging features requiring research considerations that may limit the risk of DNA transfer within packaging. [ABSTRACT FROM AUTHOR]

The present work aimed to study the detection, through lateral flow immunochromatographic (LFI) tests, of saliva samples over time in three different types of fabrics, as well as, the possibility of DNA isolation and characterization from the sample tubes and the cassettes. Fifty microliters of saliva (three samples/time) were deposited in denim, cotton, and polyester. Saliva was identified by SERATEC® Amylase Test and the Crime Scene version SALIVA CS, being able to detect it up to six months of deposition, although with different band intensities. Polyester showed stronger bands than cotton, probably due to its synthetic nature, and denim, as an inked fabric, showed less band intensities. Statistical analyses confirmed significant differences among fabrics, but not over time in the same type of fabric. Total DNA from the sample tubes was successfully recovered, in contrast, from the cassettes, only polyester retrieved amplifiable DNA. These findings indicated that it is possible to recover and identify saliva up to six months after deposition, also obtaining DNA. Future research will be able to expand these results, analyzing the stability of other body fluids, and the sensitivity of lateral flow immunochromatographic tests to detect them. [ABSTRACT FROM AUTHOR]

Blood is an important physical material that may be encountered in violent crimes such as murder, assault, and rape. The examination of bloodstains is of immense value in the reconstruction of crime scenes and the potential identification of subjects and victims and their linkage to a scene. When crime scenes occur outdoors, the identification of blood evidence can become difficult with the naked eye. The objective of this research was to conduct examinations of the Bluestar reagent to determine whether it could successfully detect blood in outdoor sites after prolonged exposure to the elements and whether the identified blood could produce a DNA profile. Bluestar advertises the ability to reveal bloodstains that have been washed out, wiped off, or which are invisible to the naked eye. For this research, approximately 0.5 oz of human blood was deposited onto the soil surface of 30 plots to be tested over 10 time intervals up to 45 days. At each interval, a soil sample and a cotton swab of the plot's surface were collected for later DNA testing. Results showed a positive Bluestar reaction throughout all intervals of the experiment. DNA profiles were developed from cotton swabs while the blood was visible to the naked eye. Some of the soil samples returned weak profiles that could not be correlated to the donor. The results of this study demonstrate that even if there is a delay in locating an outdoor crime scene, the application of Bluestar is a reliable tool in the effort of locating blood evidence. [ABSTRACT FROM AUTHOR]

Blood‐contaminated fingermarks (FMs) found in violent crime scenes may directly connect the suspect to the crime by linking the FM to the suspect and the DNA from the blood to the victim. However, marks that are incomparable are considered "dead‐evidence" as the link to the suspect is lost. In this study, a novel approach was attempted to uncover the trace amount of touch DNA of the suspect in such marks. We examined the effect of two enhancement methods, ninhydrin (NIN) and amido black (AB), on DNA recovery from blood‐contaminated FMs. A total of 108 fingerprints were deposited in three sets of depleted blood prints, blood‐contaminated FMs, and latent FMs. All FMs were developed by either NIN or AB, or left undeveloped as reference followed by the quantification of the total DNA amount. This work shows that while AB had a detrimental effect on the quantity of blood‐derived DNA specifically, reducing it by half, no similar effect was observed for touch DNA in latent FMs. This reduction led to the alteration of the major‐to‐minor DNA profile ratio to 70:30, thus enabling to obtain two distinct DNA profiles of the suspect from the touch DNA as well as the victim's profile from the blood. From an operational perspective, the use of AB in crime scenes may have an added value to retrieve the crucial DNA profile of the suspect, thus resurrecting a "dead‐evidence." [ABSTRACT FROM AUTHOR]

Background: Among the physical evidence, bloodstain is one of the most common biological pieces of evidence at the crime scene, especially in violent crimes. Bloodstains are frequently seen at the crime scene and can be easily detected due to their color and structure. Because blood and bloodstains can potentially be evidence of a crime, offenders often tend to clean or wash them to get rid of relevant evidence. Some researchers think that washed bloodstains cannot obtain enough quality DNA for DNA profiling. However, some studies have shown that bloodstains on a piece of fabric can be used for DNA profiling even after washing. This study, it is aimed to determine whether a sufficient amount of DNA can be obtained for DNA profiling used for forensic purposes from blood-stained nylon and cotton fabrics washed at different temperatures such as 40 °C, 60 °C and 90 °C. Results: In this study, bloodstains were created on cotton and nylon fabrics in a representative crime scene. After washing with laundry detergent at 40 °C, 60 °C and 90 °C was performed, studies were conducted in order to make bloodstains visible and obtain DNA for genetic profiling. The result is that more DNA is lost due to easy exposure to external factors in the non-absorbent nylon fabric type compared to the absorbent cotton fabric. Moreover, the rates of obtaining DNA from bloodstains on different types of fabrics washed at several temperatures are shown in this study. Conclusions: It was determined that while a sufficient amount of DNA for the forensic genetic profiling can be obtained from cotton and nylon fabrics washed at 40 and 60 °C, a sufficient amount could not be obtained from the ones washed at 90 °C. And that shows even if bloodstained fabrics are washed at 60 °C, the fabrics still can be considered as physical evidence of the crime and can be associated with the scene, perpetrator and victim triangle. [ABSTRACT FROM AUTHOR]

Over recent years, DNA profiling techniques have become highly sensitive. Even small amounts of DNA at crime scenes can be analysed leading to new defence strategies. At court, defence lawyers rarely question the existence of a DNA trace (source level) but challenge how the DNA was transferred to the scene (activity level). Nowadays, the most common defence strategy is to claim that somebody else had stolen the defendant's gloves and used them while breaking and entering. In this study we tested this statement. Using gloves made of different material (cloth, leather, rubber) and varying secondary transfer surfaces (wood, metal, glass), we simulated a few of the most likely transfer scenarios that occur during breaking and entering. While we detected the presence of DNA on the outside of 92 of the 98 gloves tested, we observed only one case of secondary transfer in a total of 81 transfer experiments. This data demonstrates that secondary transfer under conditions resembling realistic conditions is a very rare event. [ABSTRACT FROM AUTHOR]

Sample collection at the crime scene can introduce variations in DNA recovery based upon the substrate from which a sample is collected, the material of the collection device used, or the storage conditions after collection. There are many factors during this process that can degrade the sample during drying and storage, and before DNA extraction can be performed. The purpose of this study was to evaluate and compare the performance of standard cotton swab collection with the Bode BioSafe® swab, which includes both a desiccant at the swab head and proprietary compounds to prevent degradation of the sample during sample collection and preservation. Blood and touch DNA samples were collected from porous and nonporous substrates and stored at elevated temperatures to simulate accelerated time. DNA quantification and STR profile data were used to assess the performance of the swabs. BioSafe® swab collection resulted in similar DNA yields from blood samples and significantly higher DNA yields from touch samples when compared to collection with cotton swabs. BioSafe® swabs also resulted in higher DNA integrity during long‐term storage, increased STR profile success and improved retention of low‐level contributor alleles. [ABSTRACT FROM AUTHOR]

• Improved STR profiles are obtained from 9 mm ammunition using a direct lysis method. • Successful STR profiling was achieved from both fired and unfired 9 mm cartridges. • For most samples the major profile observed matched the known handler. • 56% of profiles obtained from the direct lysis method produced LRs >1 million. Cartridge cases are often recovered from crime scenes involving firearms and, in the United Kingdom (where gun possession is strictly controlled), these are commonly from 9 mm calibre ammunition. The ability to obtain informative DNA profiles from touch DNA on recovered cartridges could have a significant impact on the investigation of that type of offence. However, this avenue may not be routinely considered as investigators in the UK have historically had a low expectation of obtaining useful DNA profiles. This stance may not be unreasonable given that (a) only trace amounts of DNA are likely to have been transferred onto the cartridge cases through handling; and (b) when the cartridge is spent, the potential deterioration of that DNA caused by the act of discharging the weapon. We introduce a novel semi-automatable method using direct lysis for the recovery of DNA from ammunition and compare it with a traditional double-swabbing method (using wet and dry swabs). DNA profiling of the DNA recovered using both methods was carried out using the ESI17 FAST STR system (Promega). This demonstrated a significant increase in DNA recovery using the direct lysis approach, and correspondingly improved STR results. We also investigated the effect on the recovery and profiling of DNA from fired, and unfired, 9 mm cartridges using the direct lysis technique. These results demonstrate that DNA suitable for STR analysis can still be recovered from fired ammunition with only slightly reduced yields compared to unfired ammunition. In these experiments, the handler of the ammunition was most commonly either the sole contributor or the major contributor to the recovered DNA profile. [ABSTRACT FROM AUTHOR]

Featured Application: This paper's application of the proposed novel method is reducing the ski-slope effect in direct PCR, thus aiding more efficient amplification of DNA obtained from crime scenes. Analytical techniques such as DNA profiling are widely used in various fields, including forensic science, and novel technologies such as direct polymerase chain reaction (PCR) amplification are continuously being developed in order to acquire DNA profiles efficiently. However, non-specific amplification may occur depending on the quality of the crime scene evidence and amplification methods employed. In particular, the ski-slope effect observed in direct PCR amplification has led to inaccurate interpretations of the DNA profile results. In this study, we aimed to reduce the ski-slope effect by using dimethyl sulfoxide (DMSO) in direct PCR. We confirmed that DMSO (3.75%, v/v) increased the amplification yield of large-sized DNA sequences more than that of small-sized ones. Using 50 Korean buccal samples, we further demonstrated that DMSO reduced the ski-slope effect in direct PCR. These results suggest that the experimental method developed in this study is suitable for direct PCR and may help to successfully obtain DNA profiles from various types of evidence at crime scenes. [ABSTRACT FROM AUTHOR]

The sufficiency of DNA evidence alone, with regard to convicting accused persons, has been interrogated and challenged in criminal cases. The availability of offender databases and the increasing sophistication of crime scene recovery of evidence have resulted in a new type of prosecution in which the State's case focuses on match statistics to explain the significance of a match between the accused's DNA profile and the crime-scene evidence. A number of such cases have raised critical jurisprudential questions about the proper role of probabilistic evidence, and the misapprehension of match statistics by courts. This article, with reference to selected cases from specific jurisdictions, investigates the issue of DNA evidence as the exclusive basis for conviction and important factors such as primary, secondary and tertiary transfer, contamination, cold hits and match probability which can influence the reliability of basing a conviction on DNA evidence alone, are discussed. [ABSTRACT FROM AUTHOR]

Introduction: Objects exposed to saliva have been shown to be a good and a valuable source of DNA for genotyping in forensic identification. Saliva can be obtained from items used in a person's activities, including cigarette butts, envelopes that are glued together by licking, toothpicks, pillows, and bite marks. The DNA found at crime scenes is often available in very limited, both in quantity and quality. Therefore, PCR amplification technology on DNA is very suitable for analyzing forensic DNA samples because it is sensitivity, fast, also not limited by DNA quality. Loci chosen were FGA and TH01 loci, because the population in Indonesia has several specific alleles that are not shared by other Asian populations. Method: This was conducted at the Human Genetic Laboratory of Universitas Airlangga, Surabaya, Indonesia, during March 2020. The ethical clearance was issued by the Health Research Ethical Clearance Commission Faculty of Dental Medicine, Universitas Airlangga, under ethical clearance number: 155 / HRECC.FODM / III / 2020. The samples obtained from eight female volunteers who still have complete permanent teeth. Each volunteer repeated the steps until they produced 4 toothpicks. Then, the toothpicks were placed in an envelope and then stored in a room with a stable temperature for 1, 3 and 7 days. Then, DNA extraction process was started, and analysis using PCR. Results: A significant difference of DNA quantity was found quantity on day 1 and day 3, also on the 3rd and 7th day. Meanwhile, there is no significant difference between other variables. The visualization of the electrophoresis results in study was carried out at the FGA and TH01 loci and bands clear. Discussion: The advantage of toothpicks is that they are easy and comfortable. According to the quantity and quality of DNA in a person's saliva after eating or before eating does not have a difference, so this is possible if someone who has a habit biting a toothpick, then the toothpick can become evidence if it is found at a crime scene. Therefore further research is needed. In addition, this study found that DNA levels on day 0 and 7 did not have a significant difference, so that further research could be carried out with a longer exposure time and in different environmental conditions. Conclusion: Based on the analysis of the DNA quantity on toothpicks, DNA isolation from toothpick evidence might be an alternative to DNA identification in the forensic field even though it has been left for 7 days. [ABSTRACT FROM AUTHOR]

Investigative genetic genealogy (IGG) is a new technique for identifying criminal suspects that has sparked controversy. The technique involves uploading a crime scene DNA profile to one or more genetic genealogy databases with the intention of identifying a criminal offender's genetic relatives and, eventually, locating the offender within the family tree. IGG was used to identify the Golden State Killer in 2018 and it is now being used in connection with hundreds of cases in the USA. Yet, as more law enforcement agencies conduct IGG, the privacy implications of the technique have come under scrutiny. While these issues deserve careful attention, we are concerned that their discussion is, at times, based on misunderstandings related to how IGG is used in criminal investigations and how IGG departs from traditional investigative techniques. Here, we aim to clarify and sharpen the public debate by addressing four misconceptions about IGG. We begin with a detailed description of IGG as it is currently practiced: what it is and—just as important—what it is not. We then examine misunderstood or not widely known aspects of IGG that are potentially confusing efforts to have constructive discussions about its future. We conclude with recommendations intended to support the productivity of those discussions. [ABSTRACT FROM AUTHOR]

The advent of DNA profiling in the 1980s has revolutionised forensic science. Forensic DNA profiling is a powerful tool that is used to both exonerate and implicate persons of interest in criminal cases. The technologies used to recover and detect DNA from crime scene stains have evolved over time. Whereas 30 years ago most forensic profiles were generated from visible stains such as blood or semen, nowadays, DNA profiles are often generated from trace amounts of DNA including touched items. The DNA in these profiles is often compromised in quantity and quality, and frequently originates from more than one individual. This improved sensitivity has complicated the interpretation of forensic DNA profiles, and consequently improved methods of profile interpretation have had to be developed. The adoption of these methods has meant that forensic scientists can now interpret mixed DNA profiles previously thought to be too complicated. This article reviews the history of forensic DNA profiling globally, introduces the challenges of DNA profile interpretation, discusses why the community is adopting improved methods, and reflects on what new technology is on the horizon and the new challenges that may present. [ABSTRACT FROM AUTHOR]

Short tandem repeat (STR) profiling of DNA has become ubiquitous in forensic practice and is used to associate people, objects, and places with each other and with crimes. STRs can include or exclude a suspect or victim as the donor of biological evidence. In the absence of a matching profile, however, STRs have limited value. It is possible, then, to extract other information from the DNA that might lead forensic investigators to an offender. Examples include biogeographical ancestry (BGA) and externally visible characteristics (EVCs). These require alternative genetic markers including single nucleotide polymorphisms and microhaplotypes which can be genotyped on many different platforms including capillary electrophoresis, microarrays, and massively parallel sequencing (MPS). The Genetic Ancestry Lab (GAL) in Australia provides estimates of BGA and EVCs derived from DNA that is extracted from biological evidence and then subjected to targeted amplicon enrichment and subsequent MPS. This review will describe the process of BGA prediction employed by the GAL as well as describing alternative practices. Limitations are addressed and future directions highlighted, including resolution of genetic admixture. It is highly likely that inference of BGA will become standard forensic practice, performed simultaneously with or in addition to STR profiling, and it is hoped that this review might provide a road map. This article is categorized under:Forensic Anthropology > Ancestry DeterminationForensic Science in Action/Crime Scene Investigation > From Traces to Intelligence and EvidenceForensic Biology > Ancestry Determination using DNA MethodsForensic Biology > Forensic DNA Technologies [ABSTRACT FROM AUTHOR]

The persistence of DNA on washed items as well as the DNA transfer has become a major subject of research in recent years, especially after the detectability of minor DNA traces was heavily increased by sensitive analysis methods. Nowadays, the attribution of a DNA trace to an individual is only rarely questioned, whereas the way of application of this DNA to an item is subject to much discussion and speculation. Additionally, the removal of DNA by cleaning or its possible persistence on an item despite a cleaning process are often important problems in court. The aim of this study was to investigate whether DNA traces (blood, saliva, epithelial cells) on different objects (knives, plates, glasses, and plastic lids) can persist on the surface despite cleaning by different methods like hand-washing or the use of a dishwasher. In total, 120 samples were collected from artificially constructed blood, saliva, and epithelial cell stains on objects with smooth surfaces after washing and analyzed by STR amplification. Samples taken after rinsing or hand-washing resulted mainly in complete DNA profiles (62.5% of samples), while cleaning in the dishwasher rendered almost everything completely DNA-free. Since in the hand-washing experiments a secondary transfer of DNA through the water could not be ruled out, additional transfer experiments were conducted with blood and saliva samples on plates. Here, a carryover of DNA traces could be demonstrated up to the fifth washed item. [ABSTRACT FROM AUTHOR]

The article focuses on the issues regarding DNA phenotyping and virtual autopsies which are used in forensic sciences. It mentions DNA phenotyping help to solve the secrets of crime scenes and technological advances have helped to progress the degree to which experts forward a likelihood around a hypothesis. It also mentions liquid chromatography mass spectrometry (LCMS) is one of the many technological advances that has been adopted in the forensic science.

• DNA transfer and recovery from upper garments was studied by four laboratories. • DNA yield and DNA profile composition differed among laboratories and garment areas. • Yield and profile composition was influenced by activities performed while wearing. • The wearer of a garment is frequently, but not always, observed as a contributor. • Co-habiting individuals are commonly observed in profiles from worn garments. Among the various items recovered from crime scenes or persons involved in a crime event, clothing items are commonly encountered and submitted for forensic DNA sampling. Depending on the case circumstances and the activity-of-interest, sampling of the garment may concentrate on collecting DNA from the wearer, or from one or more offenders who have allegedly contacted the item and/or wearer. Relative to the targeted DNA, background DNA already residing on the item from previous contacts, or transferred during or after the crime event, may also be collected during sampling and observed in the resultant DNA profile. Given our limited understanding of how, and from where, background DNA is derived on clothing, research on the transfer, persistence, prevalence, and recovery (TPPR) of DNA traces from upper garments was conducted by four laboratories. Samples were collected from several areas of two garments, each worn on separate working or non-working days and individually owned by four individuals from each of the four laboratories, and processed from DNA extraction through to profiling. Questionnaires documented activities relating to the garment prior to and during wearing, and reference profiles were obtained from the wearer and their close associates identified in the questionnaire. Among the 448 profiles generated, variation in the DNA quantity, composition of the profiles, and inclusion/exclusion of the wearer and their close associates was observed among the collaborating laboratories, participants, garments worn on different occasions, and garment areas sampled. [ABSTRACT FROM AUTHOR]

• We investigate a method to identify a common contributor in two mixed DNA profiles. • The discrimination power is limited by the smallest DNA contribution to the profiles. • We show good ability to find pairs of profiles with a common contributor. • This tool gives the ability to provide intelligence information. Standard practice in forensic science is to compare a person of interest's (POI) reference DNA profile with an evidence DNA profile and calculate a likelihood ratio that considers propositions including and excluding the POI as a DNA donor. A method has recently been published that provides the ability to compare two evidence profiles (of any number of contributors and of any level of resolution) comparing propositions that consider the profiles either have a common contributor, or do not have any common contributors. Using this method, forensic analysts can provide intelligence to law enforcement by linking crime scenes when no suspects may be available. The method could also be used as a quality assurance measure to identify potential sample to sample contamination. In this work we analyse a number of constructed mixtures, ranging from two to five contributors, and with known numbers of common contributors, in order to investigate the performance of using likelihood ratios for mixture to mixture comparisons. Our findings demonstrate the ability to identify common donors in DNA mixtures with the power of discrimination depending largely on the least informative mixture of the pair being considered. The ability to match mixtures to mixtures may provide intelligence information to investigators by identifying possible links between cases which otherwise may not have been considered connected. [ABSTRACT FROM AUTHOR]

If an unambiguous single-source DNA profile is obtained from a crime scene, then a potential person of interest can either match or not match the crime scene profile and the likelihood ratio for the single matching genotype can be easily computed. Mixed DNA profiles on the other hand are typically ambiguous and a vast number of different likelihood ratios can be obtained depending on the genotype of a potential person of interest that is compared with the mixture later. In the absence of a person of interest it can be unclear how suitable the profile is for discriminating between donors and non-donors. We introduce a simulation method to explore the range of likelihood ratios that is expected to be obtained when a non-donor or a true donor is compared with the mixed DNA profile. Sampling is conditional on the mixture deconvolution obtained using probabilistic genotyping. These simulations help to decide whether or not a (mixed) profile is suitable for comparison to a person of interest. Moreover, the methods can be used to determine whether a profile is suitable for upload to a database and whether or not potential rework could be advised. [ABSTRACT FROM AUTHOR]

Employed for the first time in 1986, DNA profiling is nowadays established as one of the most widely used forensic techniques worldwide. However, until today, no efficient sampling technique existed to collect DNA from human skin cells from a large area, not to say from the floor of an entire room. This has been extremely unfortunate, as there is enormous forensic potential in these DNA traces from the ground to provide clues as to who has been present at a particular location, i.e. at the crime scene. By desquamation, humans loose several millions of skin cells per day, everywhere they stand, sit or walk; and they can do little about it. We developed a fast and simple method by which we can make use of all those lost skin cells. We use a vacuum cleaner equipped with a specialized filter cartridge to sample the ground. Fragmentation of the filter membrane and subsequent parallel processing of the filter fragments, using a modified Chelex® 100 extraction protocol, significantly reduce the complexity of the dust mixture. In this way, a large number of interpretable major contributor DNA profiles can be generated from individuals who have been present on the sampled surface. Overall, at least 38 % of the generated DNA profiles from all sampled test areas fulfilled the criteria for submission of single major contributor profiles to the Swiss DNA database. As demonstrated through a mock crime scene scenario simulating an indoor stabbing event, the perpetrator's DNA could be found on the floor even after a very short stay in the room of less than one minute. Furthermore, already the first application of the method at a real crime scene led to relevant case information for the police. Given its large investigative potential, we recommend Total Human DNA Sampling as a helpful complemental forensic tool to conventional DNA trace collection in major crimes. • First DNA sampling method for large areas. • High percentage of database suitable DNA profiles through subsampling. • DNA profiles correspond with the presence of individuals on the sampled areas. • Detection of suspect DNA is possible after a very short stay in the room. • Total Human DNA Sampling recommended as standard for major crimes. [ABSTRACT FROM AUTHOR]

Touch DNA, also known as trace DNA, represents one of the most frequent biological traces that are often found at crime scenes. It involves the transfer of biological material from a donor to an object or to another person during physical contact. Allows to be collected as evidence when there is a lack of visible DNA (blood, hair, semen, or saliva) or fingerprints are too stained or incomplete for fingerprint analysis. The collection and interpretation of the results of touch DNA contain very valuable information and represent a very important forensic tool that can lead to the identification of a criminal and help solve the crime. In the presented study, DNA analysis was done on samples collected at a crime scene investigation in Canton Sarajevo. Standard methods for DNA isolation, amplification, and DNA profile generation were used. From a total of 83 samples collected from different substrates at crime scenes, 6 samples with full DNA profiles and 8 with partial DNA profiles were generated. Additionally, 12 mixed DNA profiles were obtained. For 46 samples, no DNA profiles were generated. This research has shown that the accuracy of DNA profiling is significantly influenced by the proper collection of touch DNA from certain substrates. Although for half of the samples, DNA profiling was unsuccessful, this is the method of choice for this type of sample. [ABSTRACT FROM AUTHOR]

Biological traces found at the crime scene are of human, animal and plant origin. Among them the most commonly present are of human origin - hair, blood, sperm, saliva, sweat and tears, but also nails, teeth and bone bits. When considering biological traces as evidence, we distinguish incontestable and debatable traces. Incontestable samples are taken from suspects, alive victims and from all other people that may have been in contact with the traces or objects at the crime scene. Debatable traces are found at the scene of events, on objects or people associated with the venue or criminal offence, whose identity and role in the event is known. When taking biological traces, it is necessary to comply with the anti-contamination and safety rules regarding handling with biological material, including self-protection measures. The goal of processing biological traces that are usable as court evidence is to provide a sufficient amount of DNA, which can be used in the individualization of each biological trace. However, in addition to this analytical step by which evidence is undoubtedly drawn from the trace, biological traces can be treated with some simpler, cheaper and less reliable methods. In this review article, we also discussed the judicial significance of sperm traces. Sperm is often analyzed for crimes impinging on sexual freedom. Hair samples can be used for toxicological analysis and to connect perpetrators to an event or victim. [ABSTRACT FROM AUTHOR]

Field based forensic tests commonly provide information on the presence and identity of biological stains and can also support the identification of species. Such information can support downstream processing of forensic samples and generate rapid intelligence. These approaches have traditionally used chemical and immunological techniques to elicit the result but some are known to suffer from a lack of specificity and sensitivity. The last 10 years has seen the development of field-based genetic profiling systems, with specific focus on moving the mainstay of forensic genetic analysis, namely STR profiling, out of the laboratory and into the hands of the non-laboratory user. In doing so it is now possible for enforcement officers to generate a crime scene DNA profile which can then be matched to a reference or database profile. The introduction of these novel genetic platforms also allows for further development of new molecular assays aimed at answering the more traditional questions relating to body fluid identity and species detection. The current drive for field-based molecular tools is in response to the needs of the criminal justice system and enforcement agencies, and promises a step-change in how forensic evidence is processed. However, the adoption of such systems by the law enforcement community does not represent a new strategy in the way forensic science has integrated previous novel approaches. Nor do they automatically represent a threat to the quality control and assurance practices that are central to the field. This review examines the historical need and subsequent research and developmental breakthroughs in field-based forensic analysis over the past two decades with particular focus on genetic methods Emerging technologies from a range of scientific fields that have potential applications in forensic analysis at the crime scene are identified and associated issues that arise from the shift from laboratory into operational field use are discussed. [ABSTRACT FROM AUTHOR]

Stones are frequently used as tools in criminal acts. In our department, around 5 % of all analysed crime scene related trace samples are contact or touch DNA traces swabbed from stones. These samples are primarily related to cases of damage to property and burglary. In court, questions can arise about DNA transfer and the persistence of background DNA not related to the respective crime. To shed some light on the question of how likely it is to detect human DNA as background DNA on stones from an urban environment, the surfaces of 108 stones sampled throughout the city of Bern, the Swiss capital, were swabbed. We detected a median quantity of 33 pg on the sampled stones. STR-profiles suitable for a CODIS (Combined DNA Index System) registration in the Swiss DNA database were established from 6.5 % of all sampled stone surfaces. For comparison, retrospective casework data analysis from routine crime scene samples demonstrates a success rate of 20.6 % for the establishment of CODIS-suitable DNA profiles from stones sampled for touch DNA. We further investigated how climatic conditions, location and properties of the stones affected the quantity and quality of the recovered DNA. In this study, we show that the quantity of the measurable DNA decreases significantly with increasing temperature. Furthermore, less DNA could be recovered from porous stones, compared to smooth ones. • 108 stones from the city of Bern were analyzed for human DNA. • Human DNA can be found on the majority of the stones. • Single or major profiles could be established from 6.5 % of the sampled stones. • Stone porosity and outside temperature influence the detected DNA amount. • The potential of background DNA on stones should be considered. [ABSTRACT FROM AUTHOR]

Forensic DNA analysis has the potential to provide useful information for criminal justice even in cases where there is no match, neither between the DNA profile generated from the crime scene and the existing DNA profiles in criminal databases, nor between the DNA collected at a crime scene and potential suspects. In contrast to traditional forensic genetic testing, forensic familial DNA searching does not provide evidence, but helps to generate investigative leads and narrow down the range of potential offenders. The aim of this study is to examine, whether there is a need for special regulation of this topic in Hungary. [ABSTRACT FROM AUTHOR]