William Pratt

William Pratt, a.k.a. "The Mirror Man", is a delusional teenage serial killer and stalker who appeared in Hashtag.

Background
William lost both of his parents in a car accident, and as a result, he became shy and withdrawn, being apparently unpopular at school. At high school, he befriended a fellow student and amateur writer named Connor Holt, whom he helped create "The Mirror Man", an entity in creepypasta. The lore of The Mirror Man described it as appearing in windows or mirrors behind people as they post photos of themselves (or selfies) and publish them online. When the tale of The Mirror Man became extremely popular on the Internet, William, looking up to Connor as a role model and wanting to please him, decided to give the fictional entity more popularity through a series of murders based on it. He decided to target Tara Harris, a teenage girl moonlighting as a famous online celebrity, as his first victim, likely being jealous or agitated by her popularity, which was due to her increasingly raunchy selfies and rebellious attitude.

Modus Operandi
William first targeted his first victim, Tara Harris, for her status as a popular online celebrity. He intended to kill her by shooting her with a nail-gun as a reference to The Mirror Man's clawed hands, but instead bashed her head against a mirror, then stabbed her in the abdomen and killed her by slashing her throat with a shard of the mirror; this was provoked after he saw her looking at herself in the mirror and wanted to act on the irony of her being vain. He then targeted his second victim, Alexander Chase, due to his connection with Tara. He killed him by shooting him repeatedly through the neck from behind with the nail-gun while Alexander was seated in his convertible. His third victim, Daniel Osbourne (who was an alumni at the high school William attended), was targeted after the latter posted a video on Twitter challenging him. He tortured him by shooting him repeatedly in the hand and the rear thigh with the nail-gun before stomping on the areas where the nails hit; he then executed him by shooting him repeatedly in the face.

For the first two murders, William would pose selfies with the victims and post them online with the message "Fear me"; the message for the second selfie also included "#MirrorMan" due to his dissatisfaction with being called "The Selfie Killer" at the time. Also, at the scene of Alexander's murder, he fired his nail-gun repeatedly at a sheet of paper, forming a hashtag with the holes as a calling card.

Real-Life Comparison
William's murders seem to be based on a series of attacks, all of which were isolated incidents and allegedly inspired by the Slender Man, a fictional character that originated from creepypasta. Like the perpetrators of the incidents, William attacked his victims in a manner similar to what was described in the lore of a creepypasta character; however, unlike the real-life perpetrators, William was successful in actually killing his victims. The most notable of these real-life incidents, which occurred in Waukesha County, Wisconsin, and was perpetrated by two twelve-year-old girls, identified as Morgan Geyser and Anissa Weier, was also compared to William by the BAU.

Known Victims

 * 2014:
 * November 9: Tara Harris
 * November 10: Alexander Chase
 * November 11: Daniel Osbourne
 * November 12: Kimmy

Appearances

 * Season Ten
 * "Hashtag"