Ethan ThomasAn SCU agent who was framed for the murder of two cops while investigating the crime scene of a high profile serial killer. He spends the vast majority of the game trying to clear his name and track down the real culprit. His only weapons are a tazor, his SCU gear, and whatever he can find in the ruined enviroments around him.
Rosa AngelAnother SCU agent who believes in Ethan's innocence and helps him by deciphering the various clues Ethan comes across. While she plays a fairly minor role for most of the game she shows up for the library level to assist him in person and give him a tasor upgrade. If the player chooses not to kill Serial Killer X, the Bureau tries to use her to get information out of Thomas.
Malcolm VanhornA mysterious figure who shows up to help Ethan at a few points during the game. As it turns out he is Serial Killer X's uncle and felt somewhat responsible for his actions, which is why he helps Ethan track him down.
The MatchmakerThe game opens with Ethan investigating one of his latest murders when things take a turn for the worst. His calling card is murdering young women and placing the corpses on display with a male mannequin. Found dead in the department store level, a victim of his own methods.
The TorturerA serial killer who likes to drive his victims to suicide so that he doesn't deliver the final blow. Kills the teacher who ratted him out to the cops in the abandoned school, but falls prey to Serial Killer X not long afterwards.
Serial Killer X (Leland Vanhorn)The man who killed the two cops at the beginning of the game and framed Ethan for it. He spends most of the game killing other serial killers in the same why they killed their own victims. Ethan manages to confront him near the end of the game but is stopped before either of them manage to kill the other. His ultimate fate is left up to the player to decide.
Oro Dark PrimaryThe final boss of the game who fights Ethan in a surreal landscape after stalking him throughout the rest of the game. Implied to have been involved in almost all of the events in the first game in one way or another and appears many times in Ethans mind before then. Is killed after Ethan removes several metal pieces from its body, crushes its neck, and drops it to the ground from the top of the platform he was standing on.