Summary of Offense:

Sentenced to death in Alameda County on September 8, 1993 for the January 31, 1988 murder of Luis Reyna. Zambrano, then 44 and a Berkeley Waterfront Commission member, in January 1988 tried to bludgeon to death University of California immunology professor Robert Mishell and his wife, Barbara, in their Berkeley home. The professor suffered two skull fractures; he later suffered memory problems and had to quit teaching and take a disability retirement. His wife suffered grave brain damage and was severely, permanently disabled. Zambrano, a contractor, had done remodeling work on the Mishells' home but had no other relationship with them, yet believed the Mishells were responsible for anonymous phone calls to his wife exposing his extramarital affair.

He later confessed the attempted murders to Luis Reyna, a friend and fellow waterfront commissioner, and Reyna told police. Zambrano made bail in the assault case on July 15, 1988, and Reyna was last seen alive three days later, on his way to meet with Zambrano. Reyna's decapitated and dismembered body was found eight days after that near the Lafayette Reservoir; Zambrano, meanwhile, had fled to Mexico. Federal agents arrested Zambrano in March 1989 in Palm Springs, where he had followed his girlfriend. At his 1993 trial, he admitted bludgeoning the Mishells with a meat tenderizer, but said Reyna had been shot accidentally as they struggled over a gun.