Susan Atkins aka Sadie Mae Glutz was a convicted murderer and member of the Charles Manson Family. Atkins was convicted of eight murders including that of actress Sharon Tate. Originally sentenced to death, her sentence was commuted in life in prison when the Supreme Court briefly overturned the death penalty. 
Atkins died of brain cancer on September 24, 2009.

3 1/2" x 5" USPS unmailed postcard addressed to Susan Atkins on which she husband has included the recipient's name and address in the upper left corner.
On the back the recipient was to check which boxes applied to them and their preferences.