Born in 1976, Samantha's father, J.B. Allen, was a real-estate developer who was constantly busy. While she was still young, her mother fell terminally ill with cancer. Sometime in 1982, Samantha climbed into her mother's bedside in the nighttime, seeing that her father was not there. She then spotted Allen holding a boy captive and taking him to his van. Unable to accept that her father was capable of such awful actions, Samantha repressed the memory. Things became worse for her when her mother died while she was five, and she consequently underwent grief counseling. Allen also began giving her gifts, among them a catcher's mitt, a bicycle, and a puppy that she named Randy. As a teenager, she became heavily involved with sports due to her father's commitment toward his work.
In 2012, when an emaciated boy named Angel Suarez is found and another boy, Billy Henderson, goes missing, Samantha's repressed memory comes back after she watches a news report of Angel's discovery. She goes to a local police station to report what she saw, but after spotting a photo of Allen on the wall, as he contributed to the design of the police station, Samantha quickly tells the detective of the event she witnessed and defends her father before leaving. The BAU is called in to investigate Angel's discovery, and Rossi and Prentiss, having been told by Garcia of what occurred at the police station, interrogate Samantha, who denies everything she did before leaving with Randy. However, she changes her mind and goes back to the police station, where Prentiss helps her recreate the repressed memory, causing the BAU to consider Allen as a suspect.
As a result, Samantha is instructed to wear a wire, go to her father's house, and explore the basement, where the BAU assume Allen is keeping his victims. Initially, she is reluctant, but decides to go for it. There, she tells Allen that she plans to retrieve her catcher's mitt from the basement with the intention of coaching softball. At first, he is reluctant, but he allows her to explore the basement. Unfortunately, Samantha doesn't find anything and leaves after Allen helps her find the mitt. When Prentiss further interrogates her, Samantha tells her that Allen gave her gifts and the BAU realize that he was giving her possessions the victims had on them when they were abducted. Then, she confirms that in 2004, she was given a puppy; Angel had a puppy with him when he was abducted. Samantha also tells Prentiss that Allen had his teeth recapped a few years ago and that he gives children rides on a backhoe. The BAU confirm that Allen is the unsub and arrest him before he can kill Billy. When Allen is taken into custody, he is spotted by a shocked Samantha.