Dennis Rader

Dennis Lynn Rader (born March 9, 1945), better known by his pseudonym BTK (for "bind, torture, kill"), is an American serial killer and mass murderer who killed at least ten people in Wichita and Park City, Kansas, between 1974 and 1991. Although he occasionally killed or attempted to kill men and children, Rader typically targeted women. His victims were often attacked in their homes and then bound, sometimes with objects from their homes, and either suffocated with a plastic bag or manually strangled with a ligature.

In a series of crimes that terrorized Wichita in the mid-to-late 1970s, Rader also initiated a series of taunting letters sent to police and media outlets, describing his crimes in detail and referring to himself as "BTK". In addition, he stole keepsakes from his female victims, including underwear, driver's licenses and personal items. In 1979, BTK suddenly went quiet, and despite an exhaustive investigation, the case grew into one of the most infamous cold cases in American history. Rader would later confess to killing three further victims between 1985 and 1991 that were not initially linked to BTK but were confirmed to be his doing through DNA and items found in his possession.