Born on March 6, 1962, Mary was a petty thief who worked at a grocery store alongside another petty thief named Tommy Wittman. The grocery store was frequented by Don Sanderson and his family. One day, she and Tommy were manipulated by James Stanworth to aid him in an attack on the Sanderson family at their home, which previously belonged to him but was lost by his family and therefore enraging him. On the night of March 9-10, 1985, the trio broke into the Sanderson home and carried out their attack. James stabbed Don's wife Carrie and their daughter Abby, killing them, and he prepared to kill the son Joshua, but Mary, acting on a motherly instinct over the boy, convinced him to stand down. Mary fled with Joshua and the trio got away with the murders; Don received all of the blame as he initially forgot to mention Mary's presence to investigators, which made them suspicious. In the aftermath of James's killings, she gave Joshua away to another family; Mary also had a child with James. As James moved up in society, she took advantage of his progress, extorting money from him using a video depicting the attack on the Sanderson family, which she recorded.
25 to LifeEdit
In 2010, when Don is released from prison and kills Tommy in self-defense, a panicked James decides to remove all loose ends, attacking Mary in her apartment. The BAU arrive midway into the attack, but James is able to flee and Mary dies from the inflicted injuries. At the end of the episode, the BAU identify James as her killer and arrest him.