One page (front and back) handwritten letter from sexual psychopath Dennis Rader also known as the BTK Killer.

The letter was written in July 2005 from the Sedgwick County Detention Facility a few weeks before Rader was sentenced and moved to El Dorado.

Rader has drawn Radar images atop the letter and envelope. Could this be some kind of code to the outside world, or has Rader just spun a clever take on his last name? You decide. 

Hand signed at top of fist page and signed 'Dennis' closing out the letter.