John Wayne Gacy aka the "Killer Clown" and "Pogo the Clown" was a Des Plaines, Illinois serial killer convicted of 33 murders and who was executed by the state of Illinois via lethal injection on May 10, 1994. 
 
8 1/2" x 11" one page letter dated December 1, 1985 and hand signed at the close, John. 
Gacy has included a photocopy of a cartoon showing an inmate in the electric chair.

Includes the original mailing envelope addressed to a member of his legal team and postmarked December 2, 1985 Menard, Illinois.