Former California nurse sentenced to death for killing 12 patients dies of natural causes

A former nurse sentenced to death for the killing of 12 patients at two California hospitals in 1981 has died of natural causes.

Officials at San Quentin State Prison say Robert Rubane Diaz died Wednesday morning in a hospital.

The 72-year-old Diaz had been 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 say 51 condemned inmates have died from natural causes since 1978, when California reinstated capital punishment. The compares with 17 who committed suicide and 13 who were executed.