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In 2019, the Texas Department of Public Safety (TXDPS) Texas Ranger Division (TRD) identified approximately 3300 registered sex offenders (RSOs) from whom a "lawfully owed" DNA sample was missing from the Federal Bureau of Investigation's Combined DNA Index System (CODIS). Lawfully owed DNA (LODNA) is defined as a DNA sample from a qualifying offender who should have had their sample entered into CODIS, but for unknown reasons did not. As a result of those findings, TXDPS then applied for and was awarded a grant from the Bureau of Justice Assistance's Sexual Assault Kit Initiative to collect DNA specimens from these RSOs, and to perform a statewide LODNA census. TXDPS TRD sought to determine: Are the missed DNA collection problems limited to RSO's or are they occurring among individuals with a qualifying arrest or conviction as specified by state law too? What processes are used to identify individuals who are eligible for DNA sample collection? How is an individuals' DNA collection eligibility conveyed to external agencies? The findings from TXDPS' LODNA census, identified 43,245 individuals who were likely eligible for DNA collection between 1995 and 2020, therefore indicating statewide DNA collection issues. Over 4 years, collection efforts pertaining to the aforementioned lawfully owed census, have yielded 5183 LODNA sample collections, and 276 CODIS hits. This manuscript aims to create an awareness within other agencies of the importance of implementing best practices to ensure the collection and upload of LODNA from every eligible individual. [ABSTRACT FROM AUTHOR]

The potential evidential value of male underwear in cases of alleged sexual assault is often overlooked. Male underwear can be a critical item in the investigation of alleged sexual assaults. Body fluids/DNA, which may transfer to the penis during sexual contact, may in turn transfer to the inside front of the underwear, and persist for months or years, provided the underwear are not washed. Here, we demonstrate how the case circumstances drive the sampling strategy of male underwear, in order to maximize the effectiveness of the forensic analysis. Sampling considerations including recovery methods and sampling sequence are discussed, and a methodical examination strategy of male underwear is proposed. To highlight the pertinence of male underwear to the investigation of alleged sexual assaults, three real‐life cases are discussed, in which male underwear were examined for multiple body fluids/DNA, and the findings obtained proved evidentially significant. The different cases demonstrate the versatility of male underwear examination in situations, where different body fluids and DNA may transfer based on the specific allegation, and emphasize how targeted sampling can allow the scientist to assess the probability of the findings based on two competing propositions. Accurate sampling strategies are imperative for robust probability assignment in evaluative reporting of scientific findings. [ABSTRACT FROM AUTHOR]

Forensic clinicians are often called upon to help courts determine the likelihood that someone will continue to commit sexually violent acts in the future. The utility of these evaluations depends largely on how effectively the results are communicated to and understood by the trier of fact. Actuarial results, such as those commonly reported in sexual offense risk assessments, appear particularly challenging for laypersons to understand. Using a representative sample of 206 U.S. adults, this study examines three methods of communicating actuarial risk via simulated expert testimony on participants' ratings of a hypothetical evaluee's risk of sexual re‐offending. The results suggested that all participants, regardless of how results were communicated, over‐estimated the examinee's risk level relative to the expert's probabilistic findings, but tended to agree with the expert's categorical predictions. Participants who were only shown actuarial data consistently rated the evaluee as more dangerous and likely to commit future sexually violent acts. Additionally, it was found that gender significantly impacted participants' perceptions, such that women found the evaluee more dangerousness and desired greater social distance from him. This study has implications for best practices regarding expert communication of actuarial results in cases involving sexual violence. [ABSTRACT FROM AUTHOR]

The frequent absence of a documented history of sexual assault/rape in the prior research on serial sexual murderers is curious. In order to address several methodological problems in prior research, a closed-case archival review of a nonrandom national sample of 53 serial sexual homicide cases was conducted which identified 14 offenders with a history of sexual assault/rape for an overall prevalence rate of 26.4%. Of the 14 offenders with a prior known history of sexual assault/rape, 11 (78.6%) sexually penetrated at least one of their homicide victims at the crime scene. Implications for investigation of serial sexual homicide as well as for further understanding of this exceptionally rare crime are presented. [ABSTRACT FROM AUTHOR]

While efforts have been made to reduce the pervasive backlog of sexual assault evidence collection kits, the actual laboratory process remains very time‐consuming due to the requirement of a differential lysis step before DNA purification, as well as intricate mixture analysis towards the end of the DNA workflow. Recently, an alternative, direct‐to‐amplification sperm lysis method (using 1 M NaOH) was identified. However, a direct cell lysis method for non‐sperm cells has not been identified yet. Thus, the primary objective of this work was to find an alternative method that is quick, inexpensive, and does not require multiple purification steps for the lysis of non‐sperm cells in sexual assault samples. In this study, vaginal swab samples were lysed with the control method, prepGEM™, as well as six alternative reagents: alkaline buffer with 25–200 mM NaOH, high‐salt stain extraction buffer, modified radioimmunoprecipitation assay (RIPA) buffer, mammalian protein extraction reagent (M‐PER™), digitonin buffer, and urea/thiourea buffer. Quantification using Quantifiler® Trio of vaginal and semen lysates revealed that the alkaline (25 mM NaOH) and M‐PER™ methods were efficient for the lysis of vaginal epithelial cells without substantial sperm cell lysis. Following quantification, analysis of STR profiles from vaginal lysates revealed that the M‐PER™ method showed promising results across all metrics examined, including the percentage of detected STR alleles, mean peak heights, peak height ratio, and interlocus balance. Thus, this method was recommended as an alternative to the traditional differential lysis method for non‐sperm cells given its ability to produce amplification‐ready lysates without any DNA purification step. [ABSTRACT FROM AUTHOR]

Acetone presence in human biological specimens can result from exogenous administration or endogenous production, resulting from diabetes, dietary composition, alcoholism, and stress response. Victims of drug‐facilitated sexual assaults (DFSA) are understood to experience enhanced stress. At the Harris County Institute of Forensic Sciences (HCIFS), DFSA drug testing includes analysis of volatile compounds, ethanol, methanol, isopropanol, and acetone, by headspace gas chromatography/flame ionization detection. The prevalence of acetone‐positive specimens in DFSA casework has been observed to exceed that of other human performance case types. In this report, DFSA cases received between 2019 and 2021 (n = 393) were reviewed and 41 acetone‐positive cases were detailed. Overall, nearly 11% of the DFSA cases had acetone‐positive blood or urine specimens, where 3% identified acetone only, 6% identified acetone and other drug(s), and 2% identified acetone, ethanol, and other drug(s). Acetone concentrations ranged from 0.010 to 0.147 g/100 mL in urine. Other drugs such as nor‐carboxy‐Δ9‐tetrahydrocannabinol, amphetamine, methamphetamine, ethanol, and benzoylecgonine were commonly detected. Elevated stress response encountered during DFSAs may facilitate the mechanism behind enhanced acetone production leading to increased identification. Limited availability of victim medical history precludes understanding the contribution of other disease states or physiological conditions. Nonetheless, the identification of acetone in DFSA specimens supports its potential as a biomarker of trauma in forensic toxicology casework and warrants future research within the community. [ABSTRACT FROM AUTHOR]

Drug‐facilitated sexual assault is a form of sexual violence against an individual incapacitated by alcohol and/or drugs consumed voluntarily or covertly administered. The purpose of this study was to evaluate toxicological results and the associated demographics of sexual assault‐related cases submitted to Houston Forensic Science Center from 2014 to 2020. In total, 1240 samples (1230 cases) were tested during the six‐year period that consisted of blood, urine, or both specimens. Blood was analyzed for ethanol by dual‐column headspace gas chromatography with flame ionization detection. Drug screen analysis was performed preferably on urine specimens using enzyme‐linked immunosorbent assay. Positive screening results were confirmed upon request only due to laboratory policy. A total of 22% (n = 176) of requested samples were confirmed positive. Ethanol was the most prevalent substance detected, present in 17% of the samples (n = 212), followed by 11‐nor‐9‐carboxy‐delta‐9‐tetrahydrocannabinol (THC‐COOH) (n = 118). The combination of ethanol and THC‐COOH was the most frequent one found (n = 17) in cases positive for two or more drugs (n = 101). Demographic data showed the majority of DFSA victims were white (25%) females (72%) with an average age of 27 years old (n = 348). Almost 90% of cases where the presence of drugs was confirmed resulted in no charges being made, either due to lack of suspect information or unknown reasons by the laboratory. [ABSTRACT FROM AUTHOR]

The differential separation method is key to recovering a DNA profile of the sperm donor from sexual assault samples. However, low numbers of spermatozoa from the perpetrator are often swamped by the victim's epithelial cells or lost during the separation process, with the separation process labor‐intensive, time‐consuming, and operator‐dependent. The self‐sealing filter of the i‐sep® DL spin column allows direct lysis of the substrate throughout the differential separation process while preventing intact sperm cells from passing through, maximizing DNA recovery, and separation of non‐sperm and sperm cells present. This study investigated the efficacy of a modified differential separation method, which incorporated the i‐sep® DL spin column in comparison with the conventional pellet‐based differential separation method. Using semen dilution series and mock post‐coital samples, the sensitivity, reproducibility, repeatability, and efficiency of sperm DNA recovery of the pellet‐based differential to the i‐sep® method were evaluated side by side. The i‐sep® differential method was more sensitive in capturing sperm fraction DNA, with informative semen donor alleles detected from high dilutions of semen inputs where the pellet method has been unsuccessful. The i‐sep® differential method reduces manual handling, generating repeatable, and reproducible results between operators. Re‐extraction of samples previously processed by the pellet or i‐sep® differential method showed that the pellet method failed to recover 15–88% of sperm fraction DNA, while the i‐sep® differential method was able to recover >99% in the initial extraction. The i‐sep® method is robust for processing sexual assault samples, overcoming the challenges of sperm DNA losses encountered by pellet‐based methods. [ABSTRACT FROM AUTHOR]

Crime laboratories have been faced with large casework backlogs due to lengthy processing times, limited resources and scientists, and rising crime rates. Evidence related to sexual assault crimes, specifically sexual assault kits (SAKs), heavily contribute to the reported backlogs. Although more sensitive, faster chemistries and automated techniques have been implemented over the years, the traditional STR workflow remains relatively unchanged. Enhanced workflows such as direct PCR and Rapid DNA have the potential to streamline the processing of forensic evidence items including those commonly submitted in SAKs, but the FBI QAS guidelines restrict CODIS‐approved labs from implementing these methods for forensic samples. Recent studies have shown decreased turnaround times and improved or comparable profiling success with both approaches. However, review of the literature shows a lack of in‐depth research comparing traditional DNA workflows to faster and more sensitive direct PCR and/or Rapid DNA approaches for evidentiary samples, especially for SAKs. By providing the forensic science and criminal justice communities with the strengths and limitations of direct PCR and Rapid DNA methods, stakeholders and policy makers may be better informed. [ABSTRACT FROM AUTHOR]

The prevalence of sexual assault cases and increasingly sensitive DNA analysis methods have resulted in sexual assault kit backlogs in the United States. Although traditional DNA extraction and purification utilizing detergents, proteinase K, and DTT have been the primary technique for lysing sperm cell fractions from these samples, it is labor‐intensive and inefficient regarding time and sperm DNA recovery – hindering the ability of forensic analysts to keep pace with evidence submissions. Thus, this study examined seven alternative sperm cell lysis techniques to develop a method that could efficiently lyse sperm and consistently generate high‐quality profiles while also reducing time, labor, and cost requirements. Microscopic examination of lysates indicated only Casework Direct and alkaline techniques could lyse all spermatozoa within samples, while quantification results demonstrated all methods performed comparably to the control method of forensicGEM™ Sperm (p > 0.06). Amplification with 0.25 ng DNA revealed that unpurified lysates from Casework Direct, alkaline, and NP‐40 techniques produced DNA profiles with acceptable mean STR peak heights and interlocus balance, both of which were similar to or better than the control. Overall, this study demonstrated the ability of Casework Direct, alkaline, and NP‐40 methods to efficiently lyse spermatozoa and provide high‐quality STR profiles despite the absence of a purification step. Ultimately, based on the data reported herein, alkaline lysis is the recommended alternative sperm lysis approach given its ability to generate high‐quality profiles, save time, and decrease the cost per reaction when compared to traditional sperm cell lysis methods. [ABSTRACT FROM AUTHOR]

The identification of semen during a criminal investigation may be a critical component in the prosecution of a sexual assault. Commonly employed enzymatic and affinity‐based methods for detection lack specificity, are time‐consuming, and only provide a presumptive indication that semen is present where microscopic visualization is unable to meet the throughput demands. Contrary to traditional approaches, protein mass spectrometry provides true confirmatory results, but multiday sample preparation and nanoflow sample separation requirements have limited the practical applicability of these approaches. Aiming at streamlining sexual assault screening by mass spectrometry, the work here coupled a 60‐minute rapid tryptic digestion, semenogelin‐II peptide affinity purification on an Agilent AssayMap Bravo automation platform, and a 3‐minute targeted LC‐MS/MS method on an Agilent 6495 triple quadrupole mass spectrometer operating in multiple reaction monitoring mode for detecting semenogelin‐II peptides in sexual assault samples. The developed assay was assessed using casework‐type samples and was successful in detecting trace levels (0.0001 μl) of semen recovered from both cotton and vaginal swabs, as well as semen recovered from vaginal swabs during menses or adulterated with personal lubricants. This work represents a promising technique for high‐throughput seminal fluid identification in sexual assault‐type samples by mass spectrometry. [ABSTRACT FROM AUTHOR]

Pregnancies, including ones that follow sexual assaults, occasionally produce hydatidiform moles. The alleged fathers (AFs) of moles have been tested for paternity by identifying the mole's locus phenotype—the one or two visible paternal obligate alleles (POAs) per locus. The probability that the mole inherited the POAs from the AF was divided by the probability that the mole inherited the POAs from a random man. This likelihood ratio (LR) would increase if the mole's specific genotype was known. Moles are generated in five different ways that produce five distinct genotypes. Examining a mole's multilocus STR profile reveals a mole's pathogenesis, determines locus genotypes, and increases paternity LRs. [ABSTRACT FROM AUTHOR]

Y chromosomal short tandem repeats (Y‐STRs) have been applied overwhelmingly in forensic areas for solving paternity identification and sexual assault cases. Yet the widely used Y‐STR kits contain mostly single‐copy markers, which may restrict the discrimination power. Here, a novel Y‐STR multiplex was developed and validated in order to complement the currently available Y‐STR kits, especially on differentiating male relatives. The assay includes twelve multicopy Y‐STR loci (DYF371, DYF383S1, DYS385, DYF387S1, DYS389I/II, DYF399S1, DYF404S1, DYF409S1, DYF411S1, DYS464, DYS526, DYS527; four of them are rapidly mutating ones), 1 single‐copy Y‐STR (DYS391), and Amelogenin, and was optimized to amplify at annealing temperature of 59°C and 28 cycles. Validation studies show that full profiles are obtained with 0.125 ng of male DNA. The system is capable of overcoming high concentrations of inhibitors such as hematin, EDTA, and humic acid. Besides, the results demonstrate good sizing precision and the ability to detect male‐specific profiles in male/female DNA mixtures at a ratio of 1:800. Excellent species specificity was also observed in microorganisms and non‐primates, while detectable peaks were found in some primates. Based on published genetic data, gene diversity values were above 0.7 for most of the loci in our multiplex, inferring a high capacity in discriminating unrelated and related male individuals. The kit is of great potential for forensic application. [ABSTRACT FROM AUTHOR]

International protocols for forensic investigations are often created by committee and in isolation. When field tested, the results of such tests are rarely reported to the wider forensic community. This study presents a comparative study of one such protocol, the International Protocol on the Documentation and Investigation of Sexual Violence in Conflict: Best Practice in the Documentation of Sexual Violence as a Crime or Violation of International Law. The protocol was used in a pilot study involving 20 victims of conflict‐related sexual assault in the Democratic Republic of the Congo (DRC). The results of the pilot study were compared with an existing database of 341 victims of sexual assault (also from the same region of the DRC) who were examined using another protocol developed and utilized by Medicins Sans Frontier (MSF). The results clearly indicate the international protocol was far superior in all aspects, including comprehensive data capture and ease‐of‐use. Although the MSF protocol is intended for humanitarian purposes, all medical records are subject to potential downstream forensic applications. Given constraints in funding and resources in conflict zones, the wide‐spread adoption of the full international protocol would ensure that every victim receives a complete, forensically valid examination suitable for the future pursuit of justice. [ABSTRACT FROM AUTHOR]

An increasing number of US jurisdictions have begun to submit their previously untested sexual assault kits (SAKs) for DNA testing. However, best practices for what should happen after testing are not well established. Should all cases be investigated regardless of the testing outcome or only those that returned a DNA hit? We examine an early‐adopter jurisdiction that has completed testing and investigating all 5165 previously never tested kits. We explore and compare the criminal justice outcomes and cost‐effectiveness of investigating: all cases, those with CODIS hits, and those without CODIS hits. Findings indicate the SAK initiative produced a cost savings to the community: $26.48 million ($5127 p/kit) after the inclusion of tangible and intangible costs of future sexual assaults averted through convictions, of which $9.99 million ($1934 p/kit) was from also investigating no CODIS hit cases. When considering only the costs to law enforcement, investigating all cases cost $12,000 p/additional conviction. Findings also illustrate the cost‐effectiveness of investigating no CODIS hits cases and support an "investigate all" approach. This study enhances our understanding of the economic value of what comes after testing kits and investigating cases and provides a framework for jurisdictions for prioritizing resources and maximizing outcomes from testing. [ABSTRACT FROM AUTHOR]

Total Vaporization Solid‐Phase Microextraction (TV‐SPME) relies on the same technique as standard SPME but completely vaporizes a sample extract, and analytes are sorbed directly from the vapor phase. On‐fiber derivatization may also be performed using TV‐SPME, where the fiber is first exposed to the headspace of a vial containing the derivatization agent, then exposed to a new vial containing the sample. ɣ‐Hydroxybutyric acid (GHB) and ɣ‐butyrolactone (GBL) are drugs of concern in that they may be used in drug facilitated sexual assault by surreptitiously spiking them into a victim's beverage. These drugs cause sedation, memory loss, and are difficult to detect in biological samples. One challenge in their analysis is that they can interconvert in aqueous samples, which was demonstrated in samples allowed to stand at room temperature for long periods. A volume study of GBL in water was performed with volumes ranging from 1 to 10,000 µl to compare the efficacy of TV‐SPME, headspace SPME, and immersion SPME. Lastly, water, beer, wine, liquor, and mixed drinks were spiked with either GHB or GBL with realistic concentrations (mg/ml) and microliter quantities were analyzed using a TV‐SPME Gas Chromatography‐Mass Spectrometry method. The GBL volume study demonstrated an increased sensitivity in GBL detection when TV‐SPME was utilized. Additionally, GHB and GBL were identified in various beverages at realistic concentrations. Overall, TV‐SPME is beneficial because it requires no sample preparation and uses smaller sample volumes than immersion and headspace SPME. [ABSTRACT FROM AUTHOR]

Serological screening of sexual assault evidence has traditionally focused on enzyme activity and immunochromatographic assays that provide only a presumptive indication of seminal fluid and have limited sensitivity relative to DNA testing. Seminal fluid detection based on protein mass spectrometry represents a "Next Gen" serological technology that overcomes the specificity and sensitivity limitations of traditional serological screening but requires time‐consuming sample preparation protocols. This paper describes a novel "peptidomics" approach to seminal fluid detection that eliminates the need for lengthy trypsin digestion. This streamlines sample preparation to a one‐step process followed by high‐resolution mass spectrometry to identify naturally occurring seminal fluid peptides and low‐molecular weight proteins. Multiple protein biomarkers of seminal fluid were consistently and confidently identified based on the multiplexed detection of numerous endogenous peptides. These included Semenogelin I and II (90% and 86% sequence coverage, respectively); Prostate Specific Antigen/p30 (29% sequence coverage); and Prostatic Acid Phosphatase (24% sequence coverage). The performance of this streamlined peptidomics approach to seminal fluid identification in a forensic context was also assessed using simulated casework samples of the type typically collected as part of a sexual assault examination (e.g., oral and vaginal swabs stained with semen). The resulting data demonstrate that sub‐microliter quantities of seminal fluid on cotton swabs can be recovered and reliably detected. This supports the forensic applicability of a peptidomic assay for seminal fluid identification with same‐day sample preparation and analysis. Future development and streamlined multiplex peptidomic assays for additional biological stains can easily be envisaged. [ABSTRACT FROM AUTHOR]

Alcohol and parasomnias: The statistical evaluation of the parasomnia defense in sexual assault, where alcohol is involved. In this letter, we analyze Munro's argument, explain why it is unconvincing, and offer a more complete explanation of the logical and scientific basis for the ICSD3 recommendation on alcohol intoxication and the diagnosis of parasomnia. Munro argues that the ICSD3 recommendation are supportable only if the probative value of intoxication is strong enough to completely rule out parasomnia as an explanation for criminal acts. Munro suggests that the ICSD3 recommendations may have arisen from a similar transposition - a mistaken belief that the high probability of observing drunkenness among people who are guilty of sexual assaults means that there is also a high probability of sexual assaults among people who are drunk. [Extracted from the article]

A growing number of U.S. cities and states have large numbers of unsubmitted sexual assault kits (SAKs) in police property facilities. Prior research conducted in large urban cities has found that testing these kits yields a sizable number of DNA profiles that meet FBI eligibility for upload to the national criminal DNA database CODIS (Combined DNA Index System) and uploaded profiles return a substantial number of matches to existing criminal profiles in CODIS. It is unknown whether these findings are unique to large urban cities with high crime rates. The purpose of current study was to document forensic testing outcomes from a state census of previously unsubmitted SAKs, which included large urban–suburban centers, as well as smaller cities and rural counties. We inventoried all previously unsubmitted SAKs in Michigan (N = 3422 SAKs) and submitted all kits for forensic DNA testing. A total of n = 1239 SAKs had a DNA profile that met eligibility for upload into CODIS (36.2% unconditional, 56.5% conditional CODIS eligible rate) and n = 585 SAKs yielded a CODIS Hit (17.1% unconditional, 47.2% conditional CODIS hit rate). These rates are consistent with studies from urban areas suggesting approximately half of SAKs tested yield a CODIS profile and approximately half of those uploaded profiles yield a hit. We compared SAK forensic testing outcomes by geographic and population density characteristics, and although rates were often higher in larger metropolitan areas, the obtained rates in micropolitan and rural areas suggest testing is warranted in smaller jurisdictions as well. [ABSTRACT FROM AUTHOR]

Over the past decade, the large numbers of untested sexual assault kits (SAKs) have been highlighted as a systematic problem that jeopardizes or delays justice for victims. Considering the benefits of testing SAKs, researchers have worked to shed light on why sexual assault evidence has not been effectively submitted to and processed by crime laboratories. Missing from this discourse has been an understanding of the types of practices or qualities that encourage efficiency in the testing of SAKs in crime laboratories. We analyzed results of a national survey administered to all publicly funded state and local crime laboratories (N = 132 respondents) to provide critical information about (i) the extent to which laboratories are testing all of the SAKs possible given the resources they have available; and (ii) the impact that staffing, equipment, policies, and other practices have on SAK testing efficiency. We find that the average laboratory tests only about 69% of the SAKs possible given the resources available to them. However, although technical inefficiencies explain a large proportion of the number of untested SAKs, the accumulation of untested SAKs must also be attributed to laboratories having insufficient resources (e.g., too few forensic analysts). Moreover, results from stochastic frontier models show that doubling the number of forensic analysts in the typical laboratory would allow them to expand their SAK testing capacity by nearly 50%. Implications of these findings are discussed as they relate to the prioritization of resources for crime laboratories, which often operate under strict budgetary realities. [ABSTRACT FROM AUTHOR]

DNA analysis has been widely used in the forensic field in order to contribute to identifying the perpetrator of a crime. Forensic investigation in sexual assaults usually focuses on locating and identifying biological fluids, followed by DNA analysis. The identification of certain compounds present in condoms can be useful to reconstruct the occurred event, especially in cases of sexual assaults where the DNA analysis did not show the presence of a male profile and where RNA analysis did not show the presence of sperm markers. Herein we describe the case of a woman reporting to be victim of sexual assault, who was not able to provide accurate information concerning the dynamics of the event; she remembered only forced penile–vaginal penetration by a single perpetrator. We performed short tandem repeat (STR) analyses and mRNA typing for forensic genetics testing on vaginal and rectal swabs collected on the victim, and Fourier‐transform infrared spectroscopy (FTIR) followed by chromatographic analyses for the detection of condom compounds on the same swabs. The STR analysis showed only the victim's genetic profile, and RNA analysis showed only the presence of vaginal and skin markers. In this situation, the identification of condom compounds residues on vaginal swabs became important as it complemented other collected evidences allowing the Court to reconstruct the events. A proposal of likelihood ratio (LR) calculation for the assessment of the weight of evidence in this case is described. [ABSTRACT FROM AUTHOR]

Sleep sex may be a defense for alleged sexual assault. The International Classification of Sleep Disorders (ICSD3) states: "Disorders of arousal should not be diagnosed in the presence of alcohol intoxication... The former [alcohol blackouts] are exponentially more prevalent." A panel member of ICSD3, quoting ICSD3 asserts: "alcohol intoxication should rule out a sleep‐walking defense". This implies extremely strong support for a prosecution hypothesis (Hp) over a defense hypothesis (Hd). I use Bayesian methodology to evaluate the evidential probity of alcohol intoxication. The likelihood ratio, LR, measures the amplification of prior odds of guilt, LR=Posterioroddsofguiltafterconsideringalcoholintoxication/Prioroddsofguiltbeforeconsideringalcoholintoxication. By Bayes' theorem, LR=p(alcoholintoxication,givenHp)/p(alcoholintoxication,givenHd). I use data from cross‐sectional studies of sexual assault and prevalence of alcohol use, in college students, with data from longitudinal studies, and data from the epidemiology of parasomnias to evaluate LR (alcohol). LR ~1.5 or 5, depending whether alcohol does, or does not, increase the risk of parasomnias. The proposition of extremely strong support for Hp implies a LR ~1,000,000, so the proposition in ICSD3 is not supported by formal analysis. The statistical reasoning in ICSD3 is unclear. There appears to be inversion of the Bayesian conditional (confusing intoxication given assault, and assault given intoxication) and failure to evaluate alcohol intoxication in Hd. Similar statistical errors in R. v Sally Clark are discussed. The American Academy of Sleep Medicine should review the statistical methodology in ICSD3. [ABSTRACT FROM AUTHOR]

We were presented with the STR (short tandem repeat) profiles from two separate paternity trios. Each trio consisted of a mother, an alleged father, and products of conception (POC) that contained a hydatidiform mole but no visible fetus. In both cases, antecedent pregnancies had followed alleged sexual assaults. Mole classification and pathogenesis are described in order to explain the analyses and statistical reasoning used in each case. One mole exhibited several loci with two different paternal alleles, indicating it was a dispermic (heterozygous) mole. Maternal decidua contaminated the POC, preventing the identification of paternal obligate alleles (POAs) at some loci. The other mole exhibited only one paternal allele/locus at all loci and no maternal alleles, indicating it was a diandric and diploid (homozygous) mole. In each case, traditional calculations were used to determine paternity indices (PIs) at loci that exhibited one paternal allele/locus. PIs at mole loci with two different paternal alleles/locus were calculated from formulas first used for child chimeras that are always dispermic. Combined paternity indices in both mole cases strongly supported the paternity of each suspect. [ABSTRACT FROM AUTHOR]

This study is the first to examine the background level of male DNA on underpants worn by females in the absence of sexual contact. Here, we examined 103 samples from the inside front of underpants from 85 female volunteers. Samples were examined for the presence of male DNA using NGM SElect and PowerPlex Y23 kits. Only five samples gave a "complete" Y‐STR profile, even though 83.5% of our volunteers cohabited with a male. In all cases where a partner reference sample was available, the Y‐STR profile matched the cohabiting partner. We have demonstrated that a Y‐STR profile is not expected on the inside front of underpants worn by females after social contact alone. The results of this study are informative for evaluating the significance of a Y‐STR profile on underpants in cases of alleged sexual assault. [ABSTRACT FROM AUTHOR]

Various methods have been performed to predict an unknown individual's age from biological traces in forensic investigations. A considerably accurate age prediction for the semen donor can help narrow down the search in a sexual assault case. The aim of this study was to develop an assay for age prediction from seminal stains in Han Chinese males. We built a sperm‐specific linear regression model using bisulfite pyrosequencing. Validations were conducted with a Mean Absolute Deviation from the chronological age (MAD) of 4.219 years in liquid semen, 4.158 years in fresh seminal stains, 4.393 years in aged seminal stains, and 3.880 years in mixed stains, respectively. Furthermore, our strategy enables accurate age prediction using a forensic casework sample. The strategy indicated that we produced an accurate and reliable age prediction tool for the semen donors in Han Chinese males for forensic purposes. [ABSTRACT FROM AUTHOR]

Archival medical examiner specimens may contain perpetrator DNA evidence useful in unsolved ("cold case") homicides. The Office of the Chief Medical Examiner (OCME) histology slide archives were searched for sexual assault smears for all 376 female homicides from 1990 to 1999. Of these, the OCME had sexual assault smears on 84 of which 13 slides had sperm. Of these 13, six were still unsolved. DNA profiles were obtained on all six (5 from smears and one from swabs). Combined DNA Index System (submission resulted in two matches ("hits") for new suspects. In addition, three suspects were eliminated in two cases. Our review of archival sexual assault smears resulted in DNA profiles that were able to assist in the investigation of four cold case homicide investigations. It may be worthwhile for medical examiner offices to search their archival histology slides for sexual assault smears on previously unsolved cases particularly those prior to the mid‐1990s when DNA testing was less widely available. [ABSTRACT FROM AUTHOR]

In Geneva, examination of victims of sexual assault is performed by a gynecologist and a medical examiner. 48% of the victims file a complaint and we wanted to investigate the factors leading to file a complaint, those leading the Prosecutor to go to trial, and those influencing a conviction. Between 2006 and 2012, 676 victims of sexual assault were investigated (averaged age 26 year, mean 22). Information on injuries, perpetrators, and circumstances of the assault was collected and analyzed. The attacker being the ex‐spouse or a friend and the presence of semen were factors leading to file a complaint. The assailant being a family member or ex‐spouse and the presence of genital/anal lesions were factors influencing the Prosecutor. The presence of nongenital lesions, the assailant being known by the victim, influenced conviction. This study shows that the medical examiner plays a vital role in the investigation of cases of sexual assault. [ABSTRACT FROM AUTHOR]

To combat the influx of sexual assault kits (SAKs) that need to be tested, an exploration of data from Ohio's SAK Testing Initiative was carried out to identify variables that impact whether a SAK contains a probative DNA profile that is eligible for the Combined DNA Index System (CODIS) database. A validation study was completed to confirm the existence of variable relationships from the initial examination of data; new and modified statistical models were introduced to improve the predictive accuracy to determine if a SAK will contain at least one CODIS eligible DNA profile. Descriptive statistics from the validation data set confirmed conclusions about the effects of days between the assault and kit collection, the age of the victim, and consensual sex around the time of the kit collection for obtaining CODIS eligibility of DNA. The decision tree was selected as the best model. [ABSTRACT FROM AUTHOR]

This investigation intends to study materials and techniques used for biological evidence collection in sexual assault cases and is divided into two stages: in stage one, methods for biological evidence collection (the single swab (including three variants) and the "double swab technique") were compared; in stage two, swabs' component material was compared. The sampling was composed of 42 heterosexual couples who provided mock samples. The collection methods in which the whole swab is covered by evidence presented significantly better outcomes (p < 0.001), such as the "double swab technique." Additionally, nylon swabs proved to present significantly better features regarding the capacity of sample elution, providing significantly higher amounts of DNA (p ≤ 0.034). This study provides guidelines for better collection of biological evidence regarding the collection method using a swab and the proper swab material to utilize. [ABSTRACT FROM AUTHOR]

Polydimethylsiloxane (PDMS) is commonly used to lubricate condoms. The detection of PDMS on swabs from complainants can be used to support an allegation of sexual assault. Previous research has focused on establishing analytical techniques for detecting PDMS. This research examined the persistence of PDMS on the penis, in the vagina, in the mouth, and on skin. The longest PDMS detection times were 20 h on the penis, 35 h in the vagina, and 52 h on skin. PDMS was detected up to 4 h in the mouth if the participant did not eat or drink and up to 9 h if the participant slept. PDMS was not detected in the mouth after eating or drinking. The presence of biological fluids had no detrimental effect on the analysis. Aqueous extraction of swabs for DNA did not remove any significant amount of PDMS; hence, swab remains could be subsequently analyzed for PDMS. [ABSTRACT FROM AUTHOR]

Biological evidence of sexual assault is one of the most difficult sample types to analyze in forensic laboratories. Y‐STR markers are thus a valuable tool for analyzing these samples. The aim of this project was to compare three Y‐STR commercial kits by analyzing their amplification performance on casework samples. Overall, 247 trace samples were analyzed with a Yfiler® Plus PCR Amplification Kit (Applied Biosystems), PowerPlex® Y23 (Promega®) System and AmpFLSTR® Yfiler™ PCR Amplification Kit (Applied Biosystems). Comparing the amplification performance of the three kits, the first two were significantly more sensitive than the latter (p < 0.001). For samples, with a male DNA quantity less than 0.5 ng, the PowerPlex Y23® kit was the most sensitive and best performing kit, followed by the Yfiler® Plus kit (p = 0.009). In conclusion, the Yfiler® Plus and PowerPlex Y‐23® kits are viable alternatives to older kits for samples with low amounts of male DNA. [ABSTRACT FROM AUTHOR]

Abstract: Motivated by the debate over how to deal with the huge backlog of untested sexual assault kits in the U.S.A., we construct and analyze a mathematical model that predicts the expected number of hits (i.e., a new DNA profile matches a DNA sample in the criminal database) as a function of both the proportion of the backlog that is tested and whether the victim–offender relationship is used to prioritize the kits that are tested. Refining the results in Ref. (Criminol Public Policy, 2016, 15, 555), we use data from Detroit, where government funding was used to process ≈15% of their backlog, to predict that prioritizing stranger kits over nonstranger kits leads to only a small improvement in performance (a 0.034 increase in the normalized area under the curve of the hits vs. proportion of backlog tested curve). Two rough but conservative cost‐benefit analyses—one for testing the entire backlog and a marginal one for testing kits from nonstranger assaults—suggest that testing all sexual assault kits in the backlog is quite cost‐effective: for example, spending ≈$1641 to test a kit averts sexual assaults costing ≈$133,484 on average. [ABSTRACT FROM AUTHOR]

Abstract: There is little known about sexual offenders hospitalized under forensic commitment statutes such as not guilty by reason of insanity (NGRI). We conducted a chart review to delineate the demographic, clinical, and legal characteristics of NGRI sexual offenders (n = 68) committed to the California Department of State Hospitals—Napa, including 41 found NGRI for a sexual offense and 27 found NGRI for a nonsexual offense. The two groups did not differ significantly in their demographics, psychiatric diagnoses, victim characteristics, or recidivism risk as measured by the Static‐99R. Those found NGRI for a sexual offense were older at the time of their first criminal and first violent offense, younger at the time of their committing offense, and had fewer prior total convictions and sexual offense convictions. These findings may indicate that sexual offenders found NGRI for a sexual offense are less antisocial than those found NGRI for a nonsexual offense. [ABSTRACT FROM AUTHOR]

Abstract: The Ohio Attorney General's Sexual Assault Kit (SAK) Testing Initiative has resulted in nearly 14,000 kits being processed since the initiation of the project in 2012. A logistic regression model was fit to the data from 2500 SAKs in order to determine the probability of obtaining at least one Combined DNA Index System (CODIS) eligible DNA profile based on a number of predictor variables. The probability of obtaining at least one CODIS eligible DNA profile from an SAK varied as a function of (i) days to kit collection following a sexual assault; (ii) years to kit submission to the laboratory for testing following kit collection; (iii) the age of the victim; and (iv) the occurrence of victim‐reported consensual sex around the time of the assault and/or kit collection. These findings demonstrate the utility of the statistical modeling of data obtained from the “forklift” testing approach of sexual assault kits. [ABSTRACT FROM AUTHOR]

Abstract: In this sexual assault case, the standard preliminary semen examinations could not confirm physically or biochemically whether the accused's semen had stained the victim's skirt because the skirt had been dry‐cleaned for stain removal and had been worn for more than a year after the assault. Fortunately, however, a photograph taken just after the assault was found in the court records that showed white stains on the checkered skirt. The locations of the stains were estimated based on the checkered pattern of the fabric, and microscopic examination using Baecchi's staining revealed the presence of spermatozoa. Further analysis indicated the male DNA profile generated from the sperm cells was consistent with the suspect's DNA using three multiplex STR typing systems for a total of 21 autosomal and 17 Y chromosomal short tandem repeats (STRs). Ultimately, the result of the DNA profile played a very useful role as additional evidence. [ABSTRACT FROM AUTHOR]

Sexual assault samples are among the most frequently analyzed in a forensic laboratory. These account for almost half of all samples processed routinely, and a large portion of these cases remain unsolved. These samples often pose problems to traditional analytic methods of identification because they consist most frequently of cell mixtures from at least two contributors: the victim (usually female) and the perpetrator (usually male). In this study, we propose the use of current preliminary testing for sperm detection in order to determine the chances of success when faced with samples which can be good candidates to undergo analysis with the laser microdissection technology. Also, we used laser microdissection technology to capture fluorescently stained cells of interest differentiated by gender. Collected materials were then used for DNA genotyping with commercially available amplification kits such as Minifiler, Identifiler Plus, NGM, and Y-Filer. Both the methodology and the quality of the results were evaluated to assess the pros and cons of laser microdissection compared with standard methods. Overall, the combination of fluorescent staining combined with the Minifiler amplification kit provided the best results for autosomal markers, whereas the Y-Filer kit returned the expected results regardless of the used method. [ABSTRACT FROM AUTHOR]

The persistence of sperm using confirmatory microscopic analysis, the persistence of sperm with tails, time since intercourse (TSI) analysis, and results from the acid phosphatase (AP) reaction from approximately 5581 swabs taken from circa 1450 sexual assault cases are presented. The observed proportions of sperm in the vagina and anus declines significantly after 48 h TSI, and sperm on oral swabs were observed up to 15 h TSI. The AP reaction as a predictor of sperm on intimate swabs is questioned. All AP reaction times gave a low true positive rate; 23% of sperm-positive swabs gave a negative AP reaction time. We show the AP reaction is an unsafe and an unreliable predictor of sperm on intimate swabs. We propose that TSI not AP informs precase assessment and the evaluative approach for sexual assault cases. To help inform an evaluative approach, TSI guidelines are presented. [ABSTRACT FROM AUTHOR]

Connection of a perpetrator to a sexual assault is best performed through the confirmed presence of semen, thereby proving sexual contact. Evidentiary items can include sanitary napkins or diapers containing superabsorbent polymers ( SAPs), complicating spermatozoa visualization and DNA analysis. In this report, we evaluated the impact of SAPS on the current forensic DNA workflow, developing an efficient centrifugal protocol for separating spermatozoa from SAP material. The optimized filtration method was compared to common practices of excising the top layer only, resulting in significantly higher sperm yields when a core sample of the substrate was taken. Direct isolation of the SAP-containing materials without filtering resulted in 20% sample failure; additionally, SAP material was observed in the final eluted DNA samples, causing physical interference. Thus, use of the described centrifugal-filtering method is a simple preliminary step that improves spermatozoa visualization and enables more consistent DNA yields, while also avoiding SAP interference. [ABSTRACT FROM AUTHOR]

A growing number of U.S. cities have large numbers of untested sexual assault kits ( SAKs) in police property facilities. Testing older kits and maintaining current case work will be challenging for forensic laboratories, creating a need for more efficient testing methods. Methods: We evaluated selective degradation methods for DNA extraction using actual case work from a sample of previously unsubmitted SAKs in Detroit, Michigan. We randomly assigned 350 kits to either standard or selective degradation testing methods and then compared DNA testing rates and CODIS entry rates between the two groups. Results and conclusions: Continuation-ratio modeling showed no significant differences, indicating that the selective degradation method had no decrement in performance relative to customary methods. Follow-up equivalence tests indicated that CODIS entry rates for the two methods could differ by more than ±5%. Selective degradation methods required less personnel time for testing and scientific review than standard testing. [ABSTRACT FROM AUTHOR]

There are only a few cases of drug-facilitated sexual assaults on children reported in the literature so far. Here, a case of a four-year-old boy is presented. He was unconscious, and the accompanying adults reported that the child had been at a playground on his own. Returning home, he complained of having been stung and collapsed immediately. Urine and serum samples of the child were investigated. In the toxicological analysis, xylazine, a sedative and muscle relaxant used in animals, was detected. Subsequent quantification by GC/ MS after solid-phase extraction revealed 0.053 mg/L xylazine in serum and approximately 0.63 mg/L in urine. Furthermore, the child was examined by a forensic medical specialist. Police investigations revealed that the godfather, who had been previously accused of sexual abuse of children, had injected the child with the drug, possibly in preparation for a shared bath. [ABSTRACT FROM AUTHOR]

Saliva plus DNA from a suspect is commonly encountered in sexual assault cases on bodily swabs. However, without background knowledge, the weight of this evidence is unknown. It may indicate the presence of saliva resulting from cunnilingus, or it may represent indirect transfer. In this study, females who refrained from cunnilingus donated 43 items of underwear and 19 vaginal swabs. The samples were subjected to Phadebas®, RSID™-Saliva and mRNA profiling and were subsequently DNA-profiled to determine the prevalence of background saliva in the female population. The results report that 15.8% of females who refrained from cunnilingus were positive for saliva and a further 10.5% also had DNA from unknown source(s). These findings of the rate of indirect transfer were evaluated with the Bayesian approach, and it was found that the evidence of saliva plus a high foreign DNA source adds moderately strong support to the allegation of cunnilingus. [ABSTRACT FROM AUTHOR]

This single-blinded, randomized validation study was conducted to evaluate whether fluorescence under alternate light sources ( ALS) is sufficient to diagnose subclinical bruising (bruising not visible under white light). Standardized trauma was induced on randomly selected ventral forearms. On days 1, 7, and 14 investigators independently examined case forearms under white light for perceived bruising and under ALS for fluorescence and compared body maps. 56 case and 62 control forearms ( n = 118) were examined. Sensitivity of ALS on days 1, 7, and 14 was 76.8%, 69.6%, and 60.7%, respectively, compared to 69.6%, 60.0%, and 32.1% for white light. The specificity of ALS on days 1, 7, and 14 was 51.6%, 59.7%, and 53.2%, respectively, compared to 71.0%, 81.4%, and 86.9% for white light. ALS has increased sensitivity yet low specificity compared to white light in accurately detecting bruises. Fluorescence under ALS is not sufficient to accurately or responsibly diagnose subclinical bruising. [ABSTRACT FROM AUTHOR]

This study investigated the characteristics of abuse suffered by children, the dimensions of the psychiatric effects associated with abuse, and the factors affecting these. One thousand two cases aged under 18, exposed to sexual abuse, and referred over a 7-year period were assessed. Girls represented 80.8% of cases, and the numbers rose with age. The aggressors were all male, and 88.2% were known to their victim. Approximately half the children were exposed to sexual abuse involving penetration. Psychological pathology was identified in 62.1%. Female gender, the presence of penetration, physical violence, and incest significantly increased the development of psychological pathology. Levels of awareness in people close to and trusted by the child must be raised to minimize the adverse effects of trauma in the long term, preventive measures must be taken, and medical and social support units from which victims can receive assistance need to be established. [ABSTRACT FROM AUTHOR]

Forensic practitioners and crime laboratories regularly collect and analyze fingernail evidence; however, the best techniques for processing such evidence have not been established. In this study, numerous aspects of fingernail evidence processing-collection of exogenous cells, transportation, purification of DNA, and STR analysis-were analyzed using fingernails harboring applied blood or epithelial cells from scratchings. Autosomal STR mixtures resulted when fingernails were soaked or swabbed, while scrapings rarely generated mixtures but exhibited allelic dropout. Y-STRs yielded single source profiles, with scrapings again showing dropout. A silica-based kit extraction recovered significantly more exogenous DNA than did organic extraction, neither of which was affected by nail polish. Swabbing nails in succession resulted in some cross-contamination from exogenous material, while transporting nails together did not, although there was loss of exogenous cells. Optimized nail processing produced complete Y-STR profiles of male volunteers from female fingernails following scratchings. [ABSTRACT FROM AUTHOR]

This study examined whether flossing the teeth is a more effective collection method in recovering spermatozoa than conventional swabbing techniques. It was hypothesized that inclusion of flossing as a collection method would extend the recovery of spermatozoa to longer postcoital intervals ( PCIs). Eighteen individuals provided 174 oral cavity samples. Successful recovery of spermatozoa was assessed with respect to the collection method and reported activity in the oral cavity during the PCI. Samples were subjected to a differential extraction procedure prior to microscopic evaluation of the extracted pellet. The results indicate that swabbing is more effective than flossing when the PCI falls within 1.5-12 h. However, spermatozoa were recovered from seven floss samples where the corresponding swabs gave negative results. When combining the results from the two collection methods, the percentage of subjects from whom spermatozoa are recovered increases for each PCI beyond the 0-h interval. [ABSTRACT FROM AUTHOR]

Many protocols for the examination of sexual assault victims include the preparation of vaginal wet mount slides to determine whether sperm are present and if so, whether the sperm are motile. We have reviewed findings in 501 case reports to compare the efficiency of sperm detection on wet mounts to subsequent crime laboratory results of sperm searches on vaginal swabs. Sperm were detected on wet mounts in only 41% of cases in which sperm were detected in the crime laboratory. Motile sperm were observed in only 12% of cases reporting a 0-9 h postcoital interval; in three cases, motile sperm were seen at 15 h and beyond, indicating that motile sperm are not reliable evidence of a short postcoital interval. These findings demonstrate that wet mount examinations are of little value in guiding subsequent analyses in the crime laboratory or in corroborating other investigative aspects of the case. [ABSTRACT FROM AUTHOR]