Tom is an inmate at Waterbury prison where he is supposed to stay indefinitely. But after Sarah Bennett's return to Waterbury, Tom begins giving her advice and help in deciphering the Executioner's clues.
Eventually they both discover that the killer is choosing his victims and kill style using the Seven Deadly Sins of Man as his inspiration.
He is the seventh of the Executioner's victims, representing the sin of pride - where he was forced to fall onto a saw blade, chopping him right through the middle.
Tom started out as a priest working for the local church. Exclaiming about how Bryan, Alan, and the other "heathens" are drowning their peaceful town and making it filthy with perversion and indecency.
But during one of his speeches, a woman called Rachel Ingram (Bryan's wife), comes in and begins speaking to Tom. He falls head over heels for her and they begin an affair behind Bryan's back.
After their relationship got more involved, Tom confessed his love for Rachel. Which led her to feel bad for him and reveal that the entire affair was orchestrated by Bryan. He tells Tom that he's been filming them having intercourse as leverage against him. Threatening him to stop pitting the town against him and Alan.
After Tom and Rachel separate, Tom feels heartbroken over the betrayal which eventually leads to anger and a lust for vengeance.
So during Halloween 1988, Tom dresses in a medieval-style outfit which consists of a leather hood and black robe, and walks into the Ingram home. With Bryan assuming that the masked figure is Alan, Tom gets into the house very easily. But when the real Alan arrives, Bryan realizes that the doesn't know who the masked figure is.
While Bryan is talking to Alan about the 'stranger', Bryan turns his back and is stabbed through the chest with a machete. Afterwards he turns to Alan and holds him up against the wall. And with his machete cuts a large gash on Alan's left cheek and pushes him towards the exit, allowing him to escape.
After Rachel sees Tom pull Bryan into the next room, she attempts to run away but slips on Bryan's blood, falling to the floor and landing on her stomach. Tom shuts the door before she can get out.Turning back to Rachel, Tom stabs her though her neck and cuts his baby, Sarah, out of her stomach.
Tom was sentenced to life in prison; after police found him with newborn Sarah Bennett. Sarah returns to Waterbury 30 years later and with the help of Tom, Sarah learns about the new Executioner's murders in the present day as well as what Tom's motive was for killing her parents.
During the course of the season, it's revealed that Tom is Sarah's real father. Tom is unsure as to the validity of this idea at the start, but after obtaining a lock of her hair from Dylan, he gets Alan Henry to run a DNA test on it and it's confirmed.
It's revealed later in the season that Dylan had been sending Tom letters about his life story, and more specifically the Executioner case - which is what led Dylan to meet Sarah, and what their marriage is built on.