|“||She was the one. She was special.||”|
— Malone to Stephen
John suffered from a rare blood disorder, xeroderma pigmentosum, which caused his skin to burn every time he was exposed to light, akin to a vampire. As a result, he was disowned by his parents and sent to live with his uncle, a Vietnam War veteran named Doug Jones who bonded with him. Jones died from a heart attack on February 6, 2007, and left his home and belongings to him, though John allowed the home to be demolished and converted into a cash-only parking lot so he could gain his own access to the New York City sewer system. He spent most of his time down in the sewers, listening to all of the sounds from above the ground. At some point, he decided to seek an unconventional treatment for his disorder. As a result, John began abducting women and draining them of their blood so he could drink it, believing it to be a remedy of sorts. However, all of these women died after their attempts to escape, having cracked their skulls open when they fell because of disorientation.
On April 1, 2017, John abducts another girl, Katie Hammond, and slowly drains her of her blood in the sewers. Days later, he visits her to tell her it is her birthday, and asks what she was going to do to celebrate. She replies that she would go out to eat with her family. John then has Katie blow out his candle. The following day, John writes about Katie in his diary while sitting in his van. He then puts his hand into the sunlight and sees that his skin is not burning. Then, he opens a hatch in his van, opens the manhole cover underneath, and climbs down into the sewers to bring Katie food and Vitamin C. Then, John has Katie ask him a question; she asks if he leaves because he has a job. He confirms it and tells her about a time when he was working, a dead woman had been found nearby, having been there for weeks and no one knew about it. Later, Katie tries to escape, but she only finds a locked manhole cover. She yells for help, but no one can hear her. The following night, while John is working, a female motorist drives up to his post and asks him to tell his boss to get more lights in the parking lot; John halfheartedly replies that he will.
The next day, John returns to the sewers with food and realizes that Katie tried to escape when he notices a wound on her foot. He reminds Katie that it is dangerous, adding that if she falls, she could crack her head. Katie starts to cry and tells John that she needs to see her family. John says that he can't release her and that he hates when she cries. Afterwards, while Katie is eating, John informs her that she can hear everyone and everything up in the street level, but no one can hear her from down below. John yells out as loudly as he can to make his point, and then tells Katie about the dark and asks about her parents. He also asks Katie if she was afraid of the dark when she was young, to which she replies that she was. Then, John tells Katie about how he came to live with his uncle when his parents disowned him. Next, he asks Katie if she believes in fate; she replies that she doesn't believe in it. Then, she asks John to let her try to find a way out of the sewers; if she can't, then she will believe in fate again and stay. Convinced, John gives Katie her shoes and tells her to run. While fleeing from John, Katie finds a wrench and grabs it for self-defense.
Meanwhile, the BAU locate John's van and find his secret passageway into the sewers. They split up; Alvez explores the parking lot with Prentiss, while JJ and Stephen go down into the sewers. After entering the sewers, JJ and Stephen both split up; JJ finds Katie, while Stephen encounters John, who knocks him out. Stephen regains consciousness a few minutes later, but is disoriented. Stephen picks up his gun and goes looking for John. Speaking from the shadows, John accuses him of taking Katie away from him, but Stephen retorts that she wasn't his to keep. Then, Stephen asks John how many other victims he brought to the sewers, and John replies that he lost count. At that moment, Stephen pinpoints the direction John's voice is coming from, he turns, and shoots him twice. As John is lying on the floor bleeding to death, Stephen tells him to breathe deeply. However, due to the ringing in his ears from the gunshots, John is unable to hear him. Stephen recites a meditation from Sri Lanka, which he learned from Garcia earlier. Right before dying, John tells Stephen that he has never been anywhere, but he won't be 100,000 flies, referencing his earlier story about the dead woman. He then succumbs to his wounds, and his corpse is last seen being taken away on a stretcher.
John targeted young brunette women, usually drug addicts, but he started selecting healthier victims as he went along. After somehow abducting them, he would take them to the sewers and hold them captive for a week. All the while, John would use surgical equipment to drain them of their blood, a little amount at a time, and drink the blood. He would also give them food and drinks high in Vitamin C, so they would remain healthy despite the gradual blood loss. The victims' deaths were all unintentional; when they attempted to escape, they would eventually fall over due to disorientation, and crack their skulls open. Afterwards, John would clean the bodies with baby wipes and dump them around random areas of New York City at night, posing them in angelic positions beforehand. Because the victims were mostly drug addicts, a connection between the victims was never realized by police because investigators assumed the needle marks on their arms were from heroin needles. When he attacked Stephen Walker, he used a blunt instrument, likely a pipe, to hit him in the head from behind.
No official profile of John was made by the BAU.
Malone is partially similar to Richard Chase, a.k.a. "The Vampire of Sacremento". Both were psychotic serial killers who targeted women (though Chase also targeted males), and would drink their victims' blood because of their delusions.
- Unspecified dates from 2007 to 2017:
- At least two dozen unnamed victims
- Chloe Pettiman (her body was never found)
- Cynthia Bell (her body was never found)
- Daphne Vicker (her body was never found)
- Nora Farbinger
- Cora Tuchnan
- Grace Lee
- Shelley Gallagher
- Lisa Dewald
- April 1: Katie Hammond (abducted and drained of some of her blood; was released six days later)
- April 7: Stephen Walker (assaulted)
- John is the eighth unsub in the show's history to not have his name revealed by the end of the episode, despite being credited by said name. The previous seven are Billy Flynn, Steve, John Nichols, Owen McGregor, Don Black, Colin Dupley, and Johnson.
- John has some similarities to Bryan Hughes, a serial killer from Season Eight. Like John, Bryan was a social recluse who suffered from a rare, severe blood disorder and drained his victims of their blood so he could use it to fulfill some sort of delusional desire.
- Aspects of Malone's M.O. are similar to many previous criminals who have appeared on the show:
- Tim Vogel held each of his victims captive for a week before killing them.
- The Mill Creek Killer targeted young brunette women and killed them by blunt-force head trauma.
- Nathan Tubbs crossed his victims' arms over their chests post-mortem.
- Gina King drained her victims of their blood and drank it, being a vampirist like John.
- Ellen Connell cleaned four of her victims' bodies post-mortem.
- Patrick Sorenson unintentionally killed his first female victim by blunt-force head trauma.