Under a Ranting Elmo's Mask, A Man With a Disturbing Past.

The man in the red Elmo costume was back to work in Central Park on Tuesday, but under the mask, he was not smiling. He was behind in tips he earns by posing for photographs with tourists. He said he had gotten a late start because he was not released from a psychiatric evaluation at a nearby hospital until midmorning. ''The police asked me not to come here today,'' the man said Tuesday. ''I'm sort of sneaking back in.'' [ABSTRACT FROM AUTHOR]