Dennis Lynn Rader (born March 9, 1945) is an American serial killer who murdered 10 people in Sedgwick County (in and around Wichita, Kansas), between 1974 and 1991. He was known as the BTK killer (or the BTK strangler), which stands for "bind, torture and kill" and describes his modus operandi. He sent boastful 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, he resumed sending letters in 2004, leading to his 2005 arrest and subsequent conviction.