|Family|| Unnamed parents (both deceased)|
|Portrayed By||DJ Qualls|
|First Appearance||Extreme Aggressor|
Richard Slessman is a minor character who appeared in Extreme Aggressor.
Richard lost his parents in a fire when he was thirteen. After that, he and his sister went to live with their grandmother. Growing up to become a sociopath, Richard had an interest in serial killers and was a self-proclaimed fan of Gideon. Apparently, he also suffered from insomnia, taking medications and listening to heavy metal, more specifically Metallica's song Enter Sandman, to fall asleep. Eventually, he went to jail at the Cascadia Corrections Center for a short time. While in prison, he was frequently threatened by the other prisoners, resulting in Tim Vogel, who was a guard there, protecting him. When Richard got out, Vogel convinced him that he owed him, forcing him to aid him in his killings. Richard's exact assistance is not specified, although he apparently helped him install a webcam in the boat where Vogel kept his victims and may even have killed some of the victims himself.
When Heather Woodland was abducted by Vogel, Richard planted a time-triggered virus on an email sent from one of them to her which wiped the computer's harddrive and left a message on the screen: "For heaven's sake catch me before I kill more I cannot control myself", a reference to a message written by real-life serial killer The Lipstick Killer on the bedroom wall in a victim's house. Gideon was called in from his medical leave to assist. He put together the profile, which led them to Richard, who was arrested. Realizing that the conflicting behavior shown in the killings mean there were two unsubs, not one, they kept questioning him, asking for the name of his partner. Since Richard felt that he still owed Vogel, he refused to answer. As the BAU went to the Corrections Center to ask about his former cellmate, Charles Linder, who had died, they noticed that Vogel's key chain had the symbol for the car used to lure Heather Woodland. They realized that he was the other, dominant, member and followed him. Eventually, they were able to get Richard to give them Heather's location. He was presumably incarcerated after that.
The BAU were led to Richard through the profile created from Tim Vogel's murders. It said that the unsub would be white, in his late 20s who blends into any crowd. The violence of the crimes suggest a criminal record, such as petty crime or auto theft. He's smart, has good hygiene and follows the media's coverage of his murders. He has a car in good condition, possibly a Jeep Cherokee with tinted windows. He probably has a history of paranoia, stemming from a childhood trauma, such as the death of a relative. This paranoia suggests that he has in fact been interviewed by the police, possibly after coming forward as a witness.