A second MTB cyclist has been killed in a week after a California driver mowed down a rider along the Pacific Coast Highway on Wednesday – before getting out of his Lexus automobile, screaming about “white privilege” and gruesomely stabbing the rider to death, police report.

Emergency room physician Michael Mammone, 58, was riding in the bike lane on the Pacific Coast Highway in Dana Point around 15:00 when he stopped at a red light, a driver then intentionally rammed into him from behind at a high rate of speed, launching Mammone across the intersection according to the Orange County Sheriff’s Office.

Witnesses told police the driver, Vanroy Evan Smith, then exited his Lexus, approached Mammone with a knife and repeatedly stabbed him while screaming racial slurs about “white privilege.”

Bystanders immediately intervened, pinning Smith to the ground and providing first aid to Mammone’s life-threatening injuries until police and paramedics arrived.

Mammone was transported to Providence Mission Hospital, where he worked as an emergency room doctor, but his co-workers were unable to save him and he died. Mammone is survived by his wife, Julie, a nurse at Mission Hospital and their two sons.

“We are stunned by this devastating tragedy,” the hospital said in a statement.“The entire Mission Hospital family is grieving over the loss of an incredible physician and friend.”

Witnesses describe the weapon Smith allegedly used to stab and kill Mammone as large, long knife or machete, which was found at the scene by police in nearby bushes.

Smith was arrested and charged with murder and is being in the Los Angeles County Jail on a $1 million bail. He pleaded not guilty at his arraignment according to Orange County District Attorney Todd Spitzer.

“An innocent man is dead because he took a bike ride to enjoy a beautiful California day along the beach and he was hit with a car and stabbed to death by someone he apparently never met,” Spitzer said in a statement. “The murder of a complete stranger in broad daylight for what appears to be absolutely no reason is the stuff of nightmares.”

Mammon’s is the second MTB rider to be killed in Southern California in less than a week, Monique Parmalee died on Wednesday 25 January after being hit by a motorcyclist while training.

Photos: Fox11, Twitter, LACSO