California Highway Patrol officers are looking for the driver of a car involved in a fatal hit and run crash on Interstate 5 during Friday's commute.
The silver Toyota may have sustained damage to its right rear bumper and right rear quarter panel, CHP officers said.
Christopher Allen Isaacs, 24, of San Diego, was killed in the collision involving a car, a motorcycle and a semi at approximately 5 p.m. near the Santa Fe Drive exit in Encinitas.
Isaacs' girlfriend is hoping the driver will show compassion and turn themself in.
"If you truly didn't know what you did just come forward. They stole something very precious because it wasn't his time," said Jennifer Gonzalez.
Isaacs was on the motorcycle riding between two lanes when the driver of the Toyota switched lanes in front of him.
The collision of the car and the motorcycle pushed Isaacs underneath the 18-wheeler.
Isaacs, who was driving a 1995 gray Harley-Davidson motorcycle, died from his injuries.
Gonzalez says her boyfriend was coming from Orange County where he was exploring new job opportunities.
"Leaving Oceanside. See you soon," was the final text message Gonzalez received from her boyfriend.
A Montebello man was driving the 2014 International tractor/trailer combination. He was not injured or charged in the collision.
CHP officers are looking for anyone who may have witnessed what happened prior to the crash. Isaacs was wearing a full-faced red helmet and a dark jacket with a patch similar to the British flag on the back of the jacket, CHP said.
Anyone with information can contact the CHP at (858)637-3800.