Sullivan was last seen at the drive-through window of a Burger King restaurant on Chili Avenue in Gates, New York at 5:48 a.m. on July 7, 2007. His red 1995 Pontiac Sunfire with New York registration DXU 3048 was found abandoned at the end of Lettington Street, near a wooded area, later that day. The Burger King purchase receipt, fast food wrappers and Sullivan's bank card and phone charger were inside it. There were no signs of foul play in or around the vehicle. Sullivan was last heard from when he left a friend a voice mail at 6:10 a.m. on July 8, the day after he was last seen. He has not been seen or heard from since.

Sullivan is a graduate of Churchville-Chili High School, and was a student at Monroe Community College at the time of his disappearance. He had held a job at the college bookstore and had saved up enough money to buy his car. His hobbies include taking long walks and listening to music, and he was striving for a career in social work or the music industry. Sullivan's family stated he was not having any personal problems at the time of his disappearance, although he was unemployed. Prior to his disappearance, he had ordered some microphones and sound mixing equipment, which arrived in the mail after he went missing. His case remains unsolved.