Andrew O. Maltais was a resident of Fall River, Massachusetts, during the late 1970s. He was known to have been involved in the local sex work scene and had a history of drug use. Maltais had a prior relationship with Barbara Raposa, a 19-year-old single mother and sex worker. He believed himself to be the father of her child, which added complexity to their relationship. Maltais was also associated with individuals involved in the local sex trade, including Robin Murphy and Karen Marsden.

On the evening of November 7, 1979, Barbara Raposa was last seen by a friend who dropped her off in downtown Fall River so she could engage in sex work. She failed to pick up her son from the babysitter that night, prompting her father to report her missing the following day. Her body was discovered on January 26, 1980, in a wooded area near the R.E. Smith Company's (RESCO) plant in Fall River. An autopsy revealed that she had been killed shortly after her last known sighting, with her hands bound and her skull crushed.

Robin Murphy, a key witness for the prosecution, testified that she had met Maltais in a bar around midnight on the night of Raposa's disappearance. They proceeded to a local diner to pick up Raposa. During the drive, Maltais expressed his intention to kill Raposa due to her relationship with another man. After picking up Raposa, the trio drove to a wooded area near RESCO. Murphy remained in the car while Maltais and Raposa went into the woods. Murphy later heard Raposa scream and saw Maltais sitting on her, holding a rock above his head. Maltais returned to the car, and they left the scene. Murphy testified that Maltais threatened her to ensure her silence.

Throughout the investigation, Maltais maintained his innocence, even volunteering information to the police and attempting to assist in the investigation. However, his statements and behavior raised suspicions. He was arrested on February 7, 1980, and charged with Raposa's murder. At trial, Maltais presented an alibi, claiming he was at home with his mother on the night of the murder. Despite this, the jury found him guilty of first-degree murder on January 30, 1981. He was sentenced to life imprisonment without the possibility of parole. Maltais died in prison in 1988.