David Aggio, a Rohnert Park father of two and a state parole agent, was killed Saturday in a head-on car crash in Bakersfield.

Aggio, 54, was on a drive with his wife Kathleen, who was working temporarily in Bakersfield, when another vehicle slammed into their car, Bakersfield police said.

Aggio was killed instantly; his wife suffered minor injuries, including four broken bones and cuts to her feet and face from flying glass, according to family members who said she was treated and released from the hospital.

According to police, Rodolfo Contreras, 22, was driving a white Honda Civic southbound when he allegedly sped through the intersection on a yellow light, hit and jumped the median and slammed into Aggio's blue Ford Explorer. The violent collision sheared off the front end of the Honda.

Contreras may have been under the influence of drugs or alcohol and was administered a blood test by police, but results are not yet available, said Bakersfield Police Sgt. Joe Grubbs.

An investigation into the crash is ongoing, and no criminal charges have yet been filed, he said.

A former San Quentin prison guard, Aggio worked as a parole officer for 17 years in Santa Rosa and, most recently, in the Eureka Parole Unit.

"He was my big brother and my idol," said Ken Aggio of Cotati. "This is just a senseless tragedy."

"He was solid, through and through," said Kandace Millhouse, Aggio's former wife and mother of his children, Julian, 24, and Kayla, 20. "It's hard to believe he's gone."