A former nurse sentenced to death for the killing of 12 patients at two California hospitals in 1981 died of natural causes.
Officials at San Quentin State Prison said Robert Rubane Diaz died yesterday morning in a hospital.
The 72-year-old Diaz was on death row since June 1984.
He was sentenced to death after being convicted of killing 12 patients at two Riverside County hospitals by giving them lethal levels of a heart medication.
The patients were between the ages of 52 and 95.
Prison officials said 51 condemned inmates died from natural causes since 1978, when California reinstated capital punishment.
That compares with 17 who committed suicide and 13 who were executed.