In "Digging Your Grave with Your Teeth" he is seen sitting next to Tom in prison discussing the bible. He tells Tom that he can't keep going whereas Tom tells him that he has to, leading to the audience feeling like he knows what's going on with the killings.
In "As Water is Corrupted Unless It Moves" Robin and Sarah are discussing who the killer could be, where it is suggested that Tom is the brains of the operation and he has en accomplice on the outside. The only other person, who has visited him in prison besides Sarah, is Alan Henry. They are further suspicious of him as the killings are to do it religion, which is his profession and the fact that Tom spared Alan from death. Alan visits the prison again and gets the bag of Sarah's hair to do something with.
In "Ill-Gotten Gains" Alan gives Tom a letter containing unknown information. Meanwhile, Robin hypothesizes that Alan found out about June's infidelity and killed her and Trent. Due to Alan living at Cam's, there is no evidence of his father being a suspect. Robin and Sarah goes to the church and finds a bag containing rope, handcuffs and various weapons. Sarah tells Cam about it, and he retaliates by accussing her, Dylan and even himself of being the murderer. Later, Alan comes by the gallery and threatens Sarah not to accuse him of something she had no proof of. The next day Robin and Sarah follow Alan to an empty house, where they discover the priest forcing a woman dressed in leather to nail him to a cross.
In In the Pride of His Face the audience learn that in 1988 Tom was a priest advocating against prostitution and Alan was selling the various sex tapes that Rachel starred in. When Tom gets blackmailed by Rachel and Bryan not to interfere with their business, he killed them.
In Soon Your Own Eyes Will See we see in a flashback Cam pushing his mother Suzanne Henry down the stairs for being emotionally abusive towards him. Alan Henry, grew concerned with Cam but left him alone due to underestimating the amount of impact that event had on him. In present day Alan is getting more and more suspicious towards his son, noticing how close he is to Sarah and his lack of grief towards his late wife June, who was killed three months prior by The Executioner. Alan finds Cam's box of souvenirs from each killing and meets him at the church to tell him that he knows the truth. He confesses to loving him and worrying about him being a good father. After he tells Cam to repent, Cam strangles him while crying, saying "No one else needed to die".