LOS ANGELES — Marianne Campbell Smith's defiance of anti-mask rules didn't end at a Costa Mesa supermarket.
In an unusual move, Orange County prosecutors took her to trial.
On Wednesday, a jury found Smith, who is married to a sixth-generation heir of the Irvine development family, guilty of misdemeanor trespassing and obstructing a business or its customers.
It was the first mask-related criminal conviction in a county known for its vocal minority of anti-maskers who have staged oceanfront protests and picketed government meetings during the COVID-19 pandemic.
The jury took roughly an hour Wednesday afternoon to decide the case, which not only focused on the rights of a private business to enforce its policies but also on whether Smith's refusal to wear a mask inside the store or leave was intended to interfere with and obstruct the business.
After the verdict was read, Judge John Zitny sentenced Smith to a $200 fine, 40 hours of community service and a year of informal probation. Smith, who wore a plastic face shield in the courtroom, was also ordered to stay away from the market's Costa Mesa location for a year.
"I'm innocent," Smith said as she walked out of the courthouse. "Even though the verdict was guilty, I committed no crimes except to be able to breathe oxygen. I have a medical disability, and it was not honored at Mother's Market that day."
Orange County law enforcement has largely taken an educational approach to masks and other COVID-19 regulations, advising people to follow the rules rather than citing them.
In Costa Mesa, face coverings have been required in public since April 2020.
A Costa Mesa bar owner is the only other person in the county to be criminally charged with flouting COVID restrictions. That case was dismissed in August.