Brian Sullivan was 19, living with his parents in Chili, N. Y., in Monroe County, when he disappeared in July 2007.
Sullivan was last seen July 8, 2007 at the Burger King on Chili Avenue in Gates, a western suburb of Rochester.
CBS affiliate WROC reported that Sullivan's red Pontiac was found later that day on nearby Lettington Avenue; the doors were locked, and his wallet was in the car.
Sullivan's sister says Brian's last known communication with anyone was early that morning: "He called his best friend a little bit after 6...left him a voicemail...and then after that there was no cell activity, no text messages since his disappearance."
She also says the National Guard and police did several searches including by helicopter and horseback, but nothing has turned up.
Speaking about the search, his mother, Barbara Sullivan, told We Will Find You, "they thought as we did, that maybe he met up with someone...he left his car there and was gonna come back and get it."
Nearly four years after Brian disappeared, she's more than a little worried. "I don't have any idea for sure but I think that whatever happened it's not a good thing," she said. "I do not think Brian would leave us hanging."
Speaking to WROC, Sullivan's cousin Katie Towner echoed that sentiment, saying, "You pretty much know something happened. We're just waiting to find out what, and bring him home."
Towner said Brian had no gambling problem, no known drug problem, and that he "had money in the bank. He had just ordered some expensive stereo equipment."
Brian Sullivan was born Dec. 5, 1987. In July 2007 he was 5'11", weighed 170 lbs. and was last seen wearing blue-jean shorts, a blue pinstriped button down shirt, and a green baseball cap.
If you have information about the Brian Sullivan case, please contact the Monroe County, N.Y. Sheriff's Department at 585-753-4900, or the National Center for Missing and Exploited Children at 1- 800-The Lost.