McBride was last seen leaving her sister's apartment on Union Street in Concord, New Hampshire at 9:30 p.m. on July 13, 1984. She was planning to visit her 21-year-old boyfriend at his place of work. She did not take any of her personal belongings or clothing with her and did not have any additional cash. It's unclear whether she ever arrived to see her boyfriend. She has never been heard from again. She had a history of leaving home overnight without telling anyone, so she wasn't reported missing for a couple of days.

McBride was living with her sister at the time she disappeared; she has moved out of her parents' home a few months before. She had begun to have problems in 1983 after her family moved to another town. She was often truant, was suspended from school, and became involved with drugs. McBride regularly visited people at the state prison at the time she vanished; it is unknown whether any of the inmates are connected to her case. Despite her personal problems, her family does not believe she left of her own accord.

There were many sightings of McBride in New Hampshire, Massachusetts and New York state after her disappearance, but none of the accounts were verified and police don't believe any of them were genuine. Investigators believe McBride met with foul play and probably never left the city of Concord. Her boyfriend is considered a possible suspect in her case. McBride's parents had her declared legally dead in 1996, twelve years after her disappearance, and her mother died in 2003. McBride's case remains unsolved.