Dennis Lynn Rader is an American serial killer known as Wichita Kansas' "Bind Torture Kill" aka "BTK" who was convicted of 10 murders which occurred between 1974 and 1991. 

8 1/2" x 11" two page handwritten letter hand dated Septemner19, 2013 and hand signed four times.
BTK has drawn a cave gram at the end of the letter.
Hand signed again at the close, Dennis. Hand signed again, Dennis L. Rader, and initialed twice at the bottom of the 2nd page, DLR.

Includes the original prison stamped mailing envelope postmarked September 20, 2013 which was written completely by BTK and hand signed, Dennis L. Rader.