Herbert William Mullin was an early 1970's Santa Cruz, California serial killer born on April 18, 1947. 
Mullin was serving life in prison for 13 murders which he says he committed to prevent further natural disasters.  Mullin died of natural causes on August 18, 2022.
 
4 1/4" x 9 /2" drawing on the back of a saltines box. Mullin has drawn mountains and hand signed, HWM.
On the back Mullin has dated and hand signed, Herbert William Mullin 2/15/2008 Friday.