Collins was last seen at approximately 6:40 p.m. on February 10, 1984 in his hometown of San Francisco, California. He was last seen sitting on a bench at a bus stop on the corner of Oak Street and Masonic Avenue, waiting for a bus to take him home from basketball practice. He was witnessed talking to a tall, blond man with a large black dog at the bus stop. He has never been heard from again.

It is possible that Collins was abducted by two Caucasian men driving a four-door royal blue 1967 Ford Galaxy, but that report has never been confirmed. The northern California child killer John Dunkle is possible suspect in his case. His three known victims physically resembled Collins. Dunkel has never been charged in connection with Collins's case, however.

Collins was in the fourth grade at St. Agnes School when he disappeared. He the sixth of ten children in an Irish Catholic family, and resided in the 2500 block of Sutter Street in San Francisco. His siblings ranged in age from 7 to 19 years old in 1984. One cousin and one foster child were also living in the Collins residence. Authorities do not believe Collins ran away from home, as he got along well with his family and was not having any problems except for being bullied at school. His parents divorced amicably five after his disappearance. In 1994, they held a memorial service for him. His father founded a missing children's organization, the Kevin Collins Foundation, but it closed in 1996 due to financial constraints. Collins's case remains unsolved. His father believes he's deceased.