When she was Deirdre Fisher, she lived in Playa Vero, Florida. She also lived in Montana from 1998 to 2000. She eventually became a single parent. She frequently molested him during his childhood and was still breastfeeding him when he was seven years old. The latter led to him being bullied a lot at school when his peers found out. Though Social Services looked into the situation when the school became concerned, they didn't pursue any major legal action since breastfeeding a seven-year-old isn't a crime.
After Trevor was released from prison for sexually assaulting a classmate, he teamed up with his mother and the two of them started abducting and killing mothers. They were arrested while attempting to kill Julie Camden and her son Asher.
After Trevor killed a victim, Deirdre would always dump the bodies and clean any physical evidence.
Trevor was kept on a short leash, but was now rebelling. He was seeking his freedom from the one person who was cleaning up his murders: his mother. A public statement from the police, appealing for Deirdre to turn her son in, would probably not work. She is probably suffering from some form of untreated mental illness. She is also very protective over her relationship with her son. She had lost control and was in over her head. She is scared of what her son has become and is trying to cloak his darkness with her own.