California bicyclist struck by Lexus and then fatally stabbed by driver

A driver was arrested for allegedly running into a bicyclist and then fatally stabbing him on a Southern California roadway, authorities said. Vanroy Evan Smith, 39, of Long Beach was taken into custody Wednesday on suspicion of murder for the attack Wednesday in Dana Point.

"When deputies arrived, Smith was being detained by bystanders" before he was arrested, the Orange County Sheriff's Department said in a  news release.

He remained jailed without bail on Thursday. It wasn't immediately clear whether he had an attorney to speak on his behalf.

Michael John Mammone, 58, was in a bike lane on the Pacific Coast Highway at around 3 p.m. when he was struck from behind by a Lexus sedan in an intersection, according to the sheriff's department.

Mammone was a local emergency room physician at Providence Mission Hospital in Laguna Beach, CBS Los Angeles reported.

The collision "launched him into the intersection," sheriff's Sgt. Mike Woodroof told KNBC-TV. "At that point, the suspect drove around the victim, exited his vehicle, went back to the victim and continued to assault the victim."

The driver stabbed Mammone, who was pronounced dead at a hospital, a Sheriff's Department statement said Thursday.

Smith was arrested and a knife was seized, authorities said. Witnesses say Smith was also holding a BB gun when he approached Mammone, who was lying on the street in critical condition, CBS Los Angeles reported.

Smith didn't have any known connection to Mammone and investigators were still trying to determine a motive for the killing, authorities said.

"As far as relationship or motive, we have no idea at this time," Woodruff said.