A Long Beach man has been booked on suspicion of murder for allegedly hitting a bicyclist—an Orange County doctor—with his car on Pacific Coast Highway in Dana Point and then stabbing the man, who later died at a hospital.

The attack occurred for unknown reasons at about 3 p.m. Wednesday at the intersection of PCH and Crown Valley Parkway, the Orange County Sheriff’s Department reported.

“Deputies were dispatched to the intersection … (regarding) a traffic collision and an assault,” a Sheriff’s Department statement said. “Upon arrival, deputies found Michael John Mammone, 58, a cyclist, lying in the intersection suffering from severe injuries.”

Mammone died at a hospital, the Sheriff’s Department reported. Mammone was an emergency medicine doctor affiliated with hospitals including Providence Mission Hospital Laguna Beach and Mission Hills.

“Mammone was riding a bicycle facing northbound on PCH when he was struck from behind by the suspect vehicle,” the statement said. “The driver of the vehicle, Vanroy Evan Smith, 39, from Long Beach, exited his vehicle and assaulted Mammone with a knife. When deputies arrived, Smith was being detained by bystanders and was taken into custody.”

Smith was booked into the Orange County Jail on suspicion of murder, the Sheriff’s Department reported.

“A knife believed to be used in the assault was recovered at the scene,” the statement said. “At this time, there is no known connection between the suspect and the victim. Investigators will work to determine what led to this incident.”

According to Providence, Mammone was on staff at Mission Hospital since 2011.

“We are stunned by this devastating tragedy,” according to a hospital statement. “The entire Mission Hospital family is grieving over the loss of an incredible physician and friend. We will honor Dr. Mammone’s dedication to our community and passion for medicine by continuing to provide exceptional care.”

Anyone with information about the case was urged to call the Sheriff’s Department at 714-288-6740, or Orange County Crime Stoppers at 855-TIP-OCCS.

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