Richard Clarey who confessed to over 100 murders starting when he was 15 years old and living in Germany.  Clarey was sentenced to life without parole. 
Two page handwritten letter hand signed, Red. Signed again below, Clarey.
Includes the original prison issued envelope also signed in full, Richard Norbert Clarey. He has drawn what appears to be an alien on the back.

Richard Clarey Letter and Envelope Artwork Set Both Signed