DeQuina was last seen in Lynn, Massachusetts on October 3, 1979. She was living in an apartment her father owned. She asked a teenage neighbor to watch her two children so she and her boyfriend, Michele Gagnon, could go out and buy a refrigerator. The babysitter said the apartment was full of people when he arrived there and DeQuina and Gagnon left with the group after about an hour. Gagnon came back to the apartment at approximately 1:00 a.m., but DeQuina never returned home and has never been heard from again. Gabino dropped out of sight after her disappearance.

Gagnon was a member of the Hell's Angels motorcycle gang in 1979. He lived part-time with DeQuina and part-time with a friend, Robert Garbino. Several weeks after DeQuina's disappearance, Garbino was shot to death. His body was dismembered and the parts scattered on property he owned. His murder remains unsolved. Several weeks after Garbino's murder, Gagnon was also found shot to death in Bridgeport, Connecticut. His death was ruled a suicide, but police are re-investigating the circumstances. DeQuina reportedly wanted to break up with Gagnon because he and his friends were using her car to transport drugs.

DeQuina's case was reopened in 2011. Authorities believe she was murdered and they hope to identify her killer or at least find her remains.