Driver accused of intentionally crashing into cyclist in Fullerton arrested

Fullerton Police arrested a man this week they said intentionally crashed his car into a bicyclist who was riding home from work.

What we know:

Officers arrested 22-year-old Christian Diaz of West Covina on Wednesday. He was booked for attempted murder. 

The backstory:

The crash happened around 1:30 p.m. on July 22, on Orangethorpe Avenue near Harbor Boulevard. 

Jesse Costello was riding his bike home from work, when his family said he ran into the driver at a red light. The driver, the family said, was flirting with a woman who was waiting at the light. When the light turned green and the driver didn't move, Costello tapped the car's bumper to get the driver's attention.  

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The driver allegedly tried to hit Costello right then, when he was crossing the street. Costello was able to get out of the way, but wasn't so lucky the next time. 

Security video from nearby showed a red Dodge Challenger driving across several lanes of traffic to plow into Costello, sending him flipping. Costello, however was able to walk away with some bruised ribs and scrapes.

What you can do:

The Fullerton Police Department is still investigating the crash. Anyone with information should contact detectives at 714-738-6754.

The Source: Information in this story is from a press release from the Fullerton Police Department issued on Thursday, July 31, 2025, and a previous interview with the Costello family on July 24, 2025.

FullertonCrime and Public Safety