Other characteristics: Caucasian male. Brown hair, brown eyes. Sheridan had a mustache at the time of his disappearance. He wears eyeglasses.
Details at time of disappearance: Sheridan was last seen in the New York City borough of Brooklyn on December 11, 1990. He was working on a barge docked in the harbor when he left at 8:00 p.m. to call his daughter it was her fifth birthday and he wanted to wish her a happy birthday.
He never returned to the barge and his family never got a call from him, although his daughter did get a birthday card from him in the mail a few days after his disappearance. He has never been heard from again.
Sheridan graduated from the Florida Institute of Technology in 1984, with a degree in oceanographic technology. He worked as a seaman from 1975 up until the day of his disappearance his job required him to be at sea for weeks at a time. His wife described him as a reliable worker and a loving husband and father to his daughters. He had never forgotten his daughter's birthday before.
Authorities believe Sheridan probably drowned accidentally in the harbor on the night of his disappearance. He was declared legally dead in 1998, but his body was never found.