Contra Costa County DA quits after charges filed

File photo of Contra Costa County District Attorney Mark Peterson. File photo of Contra Costa County District Attorney Mark Peterson. Photo: Paul Chinn, The Chronicle Buy photo Photo: Paul Chinn, The Chronicle Image 1 of / 5 Caption Close Contra Costa County DA quits after charges filed 1 / 5 Back to Gallery

Contra Costa County District Attorney Mark Peterson resigned Wednesday in a plea deal cut on the same day state Attorney General Xavier Becerra’s office filed 13 felony charges against him in connection with his admitted use of $66,000 in campaign funds for personal expenditures.

Hours after filing the criminal case, state prosecutors appeared in a Martinez courtroom and agreed to drop 12 of the charges in exchange for Peterson’s resignation and his agreement to plead no contest to one count of perjury for making false statements on state campaign disclosure forms.

During the hearing, Contra Costa County Superior Court Judge Theresa Canepa found him guilty of the single felony and ordered him to perform 250 hours of community service and serve three years of probation. As part of the plea bargain, Peterson cannot run for public office during those years and must be booked in a county jail before the weekend.

The actions brought a remarkably swift conclusion to a rare criminal case filed by state prosecutors against an elected county district attorney.

Peterson was serving his second term in office and was seeking a third term when state prosecutors revealed last week that they were in the midst of a criminal investigation related to his campaign funds. Investigators served a search warrant at his office, and an affidavit showed they were seeking personal email, bank records, calendars and personal electronic devices that might contain evidence that Peterson engaged in perjury, embezzlement, fraud or grand theft.

At the Martinez courthouse Wednesday, Peterson’s defense attorney, Ted Cassman, likened the case to a “Shakespearean tragedy.”

Peterson may now be barred from practicing law.

“A felony conviction would be grounds for State Bar discipline,” Laura Ernde, a State Bar spokeswoman, said in an email. “If the offense involves ‘moral turpitude’ that would mean summary disbarment after the conviction is final. Otherwise, the State Bar Court would look at the circumstances and recommend discipline up to and including disbarment.”

The state attorney general’s office opened its criminal investigation after the state Fair Political Practices Commission fined Peterson $45,000 in December for using his political account to pay for non-campaign related expenses, including meals, gas, clothes, movie tickets, hotels and phone bills.

State law requires that campaign funds be used for a political, legislative or governmental purpose. The campaign watchdog found Peterson made approximately 600 personal expenditures from his campaign account, including transferring money into his personal bank account.

Peterson told commission investigators that he considered the money a loan and intended to pay it back. Commissioners opened their probe into Peterson after the district attorney notified them that he had improperly used his campaign account and was paying back the funds.

Peterson disclosed the information to the commission after he was notified by the state Franchise Tax Board in October 2015 that his political account had been selected for a routine audit.

He was first elected in 2010 then re-elected, unopposed, four years later. It’s his 2014 campaign account for which he is charged with siphoning more than $66,000 for his personal use between 2011 and 2015, according to the criminal complaint.

Last month, a Contra Costa County grand jury filed a formal accusation against Peterson related to his campaign-fund expenditures. The grand jury recommended that Peterson be removed from office. Those civil proceedings were dropped Wednesday, too, as part of the plea deal.

Melody Gutierrez and Kimberly Veklerov are San Francisco Chronicle staff writers. Email: mgutierrez@sfchronicle.com, kveklerov@sfchronicle.com Twitter: @MelodyGutierrez, @KVeklerov