Cyclist dies after being hit by car and stabbed by driver, authorities say

A California cyclist died on Thursday after being struck by a car and then stabbed to death by the driver, authorities said.

The alleged attack occurred at around 3 p.m. PT near the intersection of the Pacific Coast Highway and Crown Valley Parkway in Dana Point, a cliffside beach town located in Southern California's Orange County, some 60 miles southwest of Los Angeles. Deputies arrived at the scene to find a cyclist -- identified as 58-year-old Michael John Mammone -- "lying in the intersection suffering from severe injuries," the Orange County Sheriff's Department said in a press release.

Mammone was transported to a local hospital where he was pronounced dead, according to the sheriff's department. He worked as an emergency room physician at Providence Mission Hospital in Laguna Beach, according to Los Angeles ABC station KABC.

Investigators learned that Mammone had been riding his bicycle northbound on the scenic Pacific Coast Highway when he was hit from behind by a vehicle. The driver -- identified as 39-year-old Vanroy Evan Smith, of Long Beach -- then got out of the car and "assaulted Mammone with a knife," the sheriff's department said.

The moment of impact was captured on video by a Ring doorbell camera mounted in front of a nearby home, KABC reported.

When deputies arrived on scene, Smith was being detained by bystanders. He was subsequently taken into custody and booked into the Orange County Jail on suspicion of murder, according to the sheriff's department.

A knife believed to be used in the alleged assault was recovered from the scene, the sheriff's department said. The incident is being investigated by the Orange County Sheriff's Department Homicide Detail.

"At this time, there is no known connection between the suspect and the victim," the sheriff's department added. "Investigators will work to determine what led to this incident."

Anyone with information on the case is urged to contact the Orange County Sheriff's Department at 714-288-6740. Information may also be provided anonymously through Orange County Crime Stoppers at 1-855-TIP-OCCS.