Dennis Lynn Rader (born March 9, 1945) is an American serial killer who murdered ten people in Sedgwick County (in and around Wichita, Kansas), between 1974 and 1991.
He was known as the BTK killer (or the BTK strangler). "BTK" stands for "Bind, Torture, Kill", which was his famous signature. He sent letters describing the details of the killings to police and to local news outlets during the period of time in which the murders took place.
After a long hiatus in the 1990s through early 2000s, Rader resumed sending letters in 2004, leading to his 2005 arrest and subsequent conviction. He is currently serving 10 consecutive life sentences at El Dorado Correctional Facility, with an earliest possible release date of February 26, 2180.