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. 

4" x 6" postcard sent to BTK by a friend who has penned a handwritten message before signing the card. BTK has folded a piece of paper over the postcard and handwritten a message to his friend.