Phillip Carl Jablonski was a serial killer known as the “Deadly Urges Killer” who murdered at least 5 women. Jablonski died on California's death row December 27, 2019.

6" x 8" prison mailing envelope completely penned by Jablonski and hand signed, Phillip Carl Jablonski. 
Below the recipient's address which is obscured in the scan Jablonski has boldly printed his last name, his CDCR number and the word, "sex."