Dennis Lynn Rader is an American serial killer known as BTK, the BTK Strangler or the BTK Killer. Between 1974 and 1991, BTK killed ten people in Wichita and Park City, Kansas. Rader pleaded guilty and was sentenced to to 10 consecutive life sentences.
 
Small rock obtained in 2005 from his former residence at 6220 Independence in Park City, KS.