A Riverside County coroner involved in the investigation of one of the county's most notorious serial killers has died, coroner's officials said.
William Dykes died Wednesday from natural causes at his Riverside home. He was 88.
Dykes served two terms as county coroner, from 1978 to 1986, when it was still a stand-alone position. The sheriff now also holds the title of coroner, as well as public administrator.
Dykes headed the office during the investigation of the so-called "Lidocaine Killer," David Robert Diaz, a vocational nurse responsible for the deaths of a dozen hospital patients who ranged in age from 52 to 89.
According to published reports, Diaz murdered the men and women -- some of whom were hospitalized for treatable conditions -- by injecting them with extremely high doses of the drug lidocaine, used to control irregular heartbeats, or arrhythmia.
The killings happened in spring 1981, when Diaz was working graveyard shifts at hospitals in Banning and Perris. Authorities said Diaz had a craving for attention and would tell co-workers in advance when certain patients were likely to die.
Autopsies by coroner's officials discovered the lethal doses of lidocaine in the victims' muscle tissue, triggering an investigation which culminated in Diaz's arrest and conviction. He was sentenced to the death penalty, but died in August 2010 of a heart attack.