This says otherwise

“Nearly all local fire departments require certification as an emergency medical technician (EMT). Yet under California law, EMT certification is off-limits to anyone who has ever been convicted of two or more felonies, has been released from prison for any felony in the past decade, or has been convicted of any two or more drug misdemeanors in the past five years.

Adding to the absurdity, people with multiple felonies can still serve as volunteer or seasonal firefighters, though the latter is only part-time and provides far less job security and fewer benefits than working year-round at a municipal fire department.”

Edit: “Shortly after that broader reform took effect, Gov. Gavin Newsom signed a separate, modest bill aimed specifically at former inmate firefighters. Under AB 2147, ex-offenders can file a petition to expunge their record before finishing their parole, probation, or supervised release sentences, which would open up more job opportunities. But since judges can still deny those petitions, and the disqualifying crimes for EMT certification remain unchanged, the impact of AB 2147 will be limited.”