Dennis Lynn Rader (born March 9, 1945) is an American serial killer who murdered ten people in Sedgwick County, Kansas between 1974 and 1991. He is also known as the BTK Killer or the BTK Strangler. "BTK" stands for "Bind, Torture, Kill", which was his infamous signature. He sent letters describing the details of the murders to police and local news outlets before his arrest.