Scott Shelby, better known as the Origami Killer, is the main antagonist of the interactive 2010 mystery-drama action-adventure video game Heavy Rain. He was one of the four protagonists and one of the playable characters only to be revealed as the true killer.
In Heavy Rain
In his past, he suffered from abuse by his father. He served as US Marine and police officer. Now, he operates as a private detective and a serial killer.
The Origami Killer revealed
Near the end, The Origami Killer as a child is revealed to be Shelby himself. His real name is Scott Sheppard.
The reason he became the killer is because he has a bad childhood with an abusive father. One rainy night, while playing with his brother John in a construction site, he is trapped in a well, and Scott tries to get help from their father, but he had no desire to do so. His brother dies as a result.
After John's death Scott was taken into care and adopted by the Shelby family.
When Madison Paige comes to apartment to find Shaun Mars' location, Shelby puts her into gunpoint and traps her in his closet in order to kill her in the explosion of his apartment. It depends if she escapes or not.
Ethan Mars goes to a warehouse to save Shaun, but Shelby appears and reveals that he is one of the witnesses who saw him jumping in front a car in an unsuccessful attempt to save his first son Jason from being killed by it.
This is the reason why he became the Origami Killer, just to find a father who will give up his life for his own son. When Ethan demands Shaun to be released, Shelby let him do it, but attempts to kill him so that his identity as the killer will be protected. Norman Jayden arrives and fights Shelby in a conveyor belt. The fight results in the killer's death.