The Origami Killer is the main antagonist and perpetrator of several kidnappings and murders in the Heavy Rain world. The most recent case the killer is suspected to be involved in is the kidnapping of Shaun Mars, the son of Ethan and Grace Mars.
Prior to Shaun's abduction, eight criminal kidnappings and homicides are suspected to have been committed by the Origami Killer between the years 2009 and 2011. All victims were young boys between 9 and 13 years of age, each killed in the same fashion: by being drowned in rainwater.
Each body is found on some type of wasteland, always adjacent to train tracks, 3-5 days after they are abducted, approximately six hours post-mortem, showing that the person who orchestrated these events did not kill his victims right after abduction. Instead, the killer waits until a set of certain criteria has been filled. Every victim was in a public place at the time of the abduction and was found with few or no defensive wounds on his body, implying that the victims knew or trusted the person that took them.
Like many serial killers, the Origami Killer has a certain trademark which he leaves upon his victims. Each victim is found with an origami figure in his right hand (from which the killer's title originates) and an orchid on his chest. The victims also have their faces completely covered in mud, which FBI profiler Norman Jayden suspects is evidence that the killer himself has no personal hostility towards the victims. He also interprets the orchid and origami figure to be gifts.
There are a number of trials the Origami Killer presents to the fathers of his victims. The killer sends each father an envelope containing a letter with a poem written on it, and the key to a train station locker. Inside the locker is a shoebox containing a handgun, a mobile telephone and compatible memory card, and five different origami figures detailing the trials he must undertake.
Once the memory card is placed into the phone, a message appears on the screen asking, "How far will you go to save someone you love?" (This echoes the game's tagline.) It then cuts to a video of the abducted son, caged in a well that is gradually filling up with rainwater. Each origami figure inside the box has the address to one of the trials and a brief description of the assignment. In order for the father to save his son, he must complete each trial. Successful completion will reward him with letters hinting at the address of his son's whereabouts.
It seems that a number of fathers, like Ethan, have attempted to undergo the trials to save their sons. Most, if not all, have failed, though nothing definitive is ever said or shown.
The father of Jeremy Bowles, the eighth victim, seems to have received the same contents as Ethan, yet is only confirmed to have received the mobile phone. When he disappeared after Jeremy's disappearance, Susan Bowles attempted to activate the phone to no avail.
Hassan says that he received both the letter and the shoebox left behind by the Origami Killer, yet he seems not to have understood the purpose of its contents and was therefore unable to save his son, Reza.
Lauren Winter, mother of victim Johnny Winter, will, if asked, tell Scott Shelby that the father of her son left just after receiving the letter and that she hasn't seen him since. It's possible that he either died as a result of one of the trials or simply chose to leave.
During "The Butterfly," inside the glass-filled tunnel leading to the room with the electrical capacitors, there lies the body of a deceased man. It is suspected to be one of the fathers, before Ethan, who ventured to take part in the trial but died in the process. Given the relatively intact state of the corpse it appears not to have been there long, suggesting that this is Jeremy Bowles' father, as Jeremy was the last victim before Shaun's kidnapping.
The identity of the Origami Killer is found toward the end of the game and can be discovered by up to three of the playable characters. However, the identity is always revealed to the player by the credits.