Robert Rubane Diaz was a California coronary care nurse who murdered 12 elderly patients in 1981, making him one of the state's most notorious medical serial killers 8 /12" x 11" handwritten kite to Lawrence "Pliers" Bittaker while the two were both housed together on east block at San Quentin State Prison's notorious death row, completely handwritten by Diaz, hand signed, Bob Diaz. On the back he has handwritten twice, Bittaker #111.