Irvine man who overdosed then got into a fatal DUI crash facing a murder charge

SANTA ANA, Calif. — A 21-year-old man has been charged with murder for killing a 61-year-old woman while driving under the influence of drugs just hours after being released from the hospital following a fentanyl overdose. The driver had already been charged in a 2019 driving under the influence case in which he had been warned of the deadly dangers of driving under the influence.

Luis Marcial Diaz, 21, of Irvine, has been charged with one felony count of murder for killing Kyu Chen, 61, of Irvine, who was on her way to work.

Diaz faces a maximum sentence of 15 years to life if convicted. He is scheduled to be arraigned on October 14, 2021 in CJ1. He is currently being held at the Intake Release Center on $1 million bail.

Diaz was arrested Tuesday by the Irvine Police Department.

Just after 4 a.m. on September 27, 2021, Diaz is accused of running a stale red light at the intersection of Sand Canyon Road and Irvine Center Drive in the City of Irvine. Chen was driving through the intersection on a greenlight on her way to work when she was broadsided by Diaz’ vehicle. Chen later died.

On July 30, 2019, Diaz was arrested by the Huntington Beach Police Department on suspicion of driving under the influence of drugs. He was charged with one misdemeanor count of driving under the influence of drugs, one misdemeanor count of possession of nitrous oxide, and one misdemeanor count of driving without a valid license. He pleaded not guilty to the three misdemeanor charges.

Drivers arrested on suspicion of driving under the influence in California can be given what is known as a Watson advisement that informs them that if they kill someone while driving under the influence they can be charged with murder. Diaz received the Watson advisement in connection with his 2019 arrest for driving under the influence of drugs. The Steve Ambriz Act, authored by then-Assemblymember Todd Spitzer, requires people applying for a California driver’s license to sign a form acknowledging that they can be charged with murder if they kill someone while driving under the influence of drugs or alcohol.

“The Irvine Police Department is committed to holding accountable those who choose to drive while under the influence of drugs or alcohol,” said Irvine Police Chief Michael Kent. “Mr. Diaz showed a complete lack of regard for the lives of others when he chose to get behind the wheel that Monday morning. Our hearts go out to Mrs. Chen’s family and we hope they get the justice they deserve for this tragic loss.”

“This is a tragedy that should have never happened,” said Orange County District Attorney Todd Spitzer. “Just hours before Mrs. Chen was murdered, doctors managed to save the defendant from overdosing on drugs. Instead of taking that near-death experience to heart, he continued to engage in incredibly dangerous behavior and it cost Mrs. Chen her life. She was just driving to work and now she is dead. And the tragedy of it all, is she didn’t have to die. The Orange County District Attorney’s Office will do everything it can to ensure justice is done for Mrs. Chen and her loved ones – and to send a strong message to drivers that there are serious consequences for driving under the influence.”

Deputy District Attorney Casey Cunningham of the Homicide Unit is prosecuting this case.