One of three defendants charged with the murders last year of a Canadian tourist in San Francisco and a Lake County therapist in Marin County pleaded guilty Monday to one count of second-degree murder.
Sean Angold, 24, of San Francisco, pleaded guilty as part of a plea agreement in which he agreed to testify at the trials of his co-defendants, Lila Scott Alligood, 18, of San Rafael, and Morrison Lampley, 23, of San Francisco, Marin County District Attorney Ed Berberian said.
Angold will be sentenced to 15 years to life in prison at the conclusion of the trials, Berberian said.
The district attorney's office announced in March it will not seek the death penalty against the defendants. Alligood and Lampley face life in prison without parole if they are convicted.
All three were charged with the shooting murders of therapist Steven Carter, 67, in the Loma Alta Open Space Preserve near Fairfax on Oct. 5 and of Audrey Carey, 23, of Quebec, Canada, on Oct. 2 in Golden Gate Park in San Francisco.
"I trust that justice will be served to its fullest extent for these two unbearable murders, and that today's events will support this goal," Carter's widow, Lokita Carter, said in a statement.
The murder charges included special circumstance allegations of committing multiple murders, lying in wait and killing during the commission of a robbery.
Lampley is identified in the criminal complaint as the alleged shooter.
Carter's Volkswagen Jetta was missing and video from a surveillance camera showed the three defendants refueling the vehicle at a Point Reyes gas station.
Investigators tracked the car to Portland via the vehicle's GPS system, and the three defendants were arrested in a dining hall there on Oct. 7.
The defendants' preliminary hearing is scheduled to start May 9, and it's unknown if Angold's plea will delay the hearing. Berberian said the prosecution is ready to proceed.
NBC Bay Area's Jean Elle contributed to this report.