Mr. Diaz was arrested Nov. 23, 1981, after an investigation into the mysterious deaths of several elderly patients at the Community Hospital of the Valleys in Perris and the San Gorgonio Pass Memorial Hospital in Banning. Eleven of the 12 deaths occurred at the Perris facility in March and April 1981.

Autopsies Determined Cause

Investigators determined through autopsies that the patients were homicide victims and that the bodies contained more than 1,000 milligrams of lidocaine at the time of death. A normal dose ranges from 50 to 100 milligrams.