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. 

3 1/2" x 5" photo sent by Gacy to a friend while he was on death row.
The photo shows Gacy dressed as Pogo the Clown. 
He has written and hand signed the back, Pogo the Clown Taken 1977 Dec John W Gacy,

John Wayne Gacy Signed Pogo the Clown Photo