Police at Berkeley protest say they backed off as a safety decision

Berkeley Police stand guard as a smoke bomb is set off at Civic Center Park in Berkeley, Calif. on Sunday, August 27, 2017. Berkeley Police stand guard as a smoke bomb is set off at Civic Center Park in Berkeley, Calif. on Sunday, August 27, 2017. Photo: Scott Strazzante, The Chronicle Buy photo Photo: Scott Strazzante, The Chronicle Image 1 of / 92 Caption Close Police at Berkeley protest say they backed off as a safety decision 1 / 92 Back to Gallery

The decision by police to step aside and allow black-clad demonstrators to take over Martin Luther King Jr. Civic Center Park on Sunday was based on the safety of officers and protesters, a spokeswoman for the Berkeley Police Department said.

For hours, some 400 law enforcement officers from Berkeley, Oakland, UC Berkeley and Alameda County had control of the scene at the park, stopping anyone who entered at a single checkpoint, where they confiscated anything on a list of banned objects, including skateboards, eggs and any items that could be used as weapons.

But shortly after the scheduled 1 p.m. start time of an anti-Marxism rally, hundreds of black-masked agitators arrived at the scene. Rather than trying to take on the horde, the clearly overwhelmed police force allowed hundreds of people to pass barriers and enter the park unchecked.

“We made a strategic decision to move our officers,” Berkeley police spokeswoman Officer Jennifer Coats said. “We also want people to freely assemble.”

Once in, the masked agitators beat and pepper-sprayed right-wing demonstrators, who were far outnumbered in the crowd. Mobs chased some of the right-wingers — a few dressed to show their support for President Trump — into the streets.

Wearing gas masks on the outskirts of the park, riot officers continued to attempted to control several fights using smoke canisters. Police arrested 13 people, including one on suspicion of assault with a deadly weapon. Most were arrested in connection with banned items.

Before things got unruly, police had a zero-tolerance policy, immediately squelching any skirmishes and swiftly removing agitators from the heavily fortified park throughout the morning.

“We tried to address things at the beginning. We tried to make sure things stayed peaceful,” Coats said. “We have to go through these things fairly often, so we try new and different strategies. Some work and some don’t. We’re learning.”

The tactical approach came as law officials around the country have begun re-evaluating how they monitor and intervene at such rallies, after a deadly protest involving white supremacists in Charlottesville, Va., on Aug. 12.

The Berkeley City Council passed an emergency ordinance last week allowing the city to issue temporary rules for nonpermitted public events like Sunday’s. The new rules follow two violent clashes in Berkeley in April between similar groups.

On Sunday, the strategy of using overwhelming resources to preempt problems was similar to the approach taken by authorities in San Francisco a day earlier in response to a planned rally by the conservative group Patriot Prayer.

That group’s organizer, Joey Gibson, had to be rescued by officers in Berkeley Sunday as he was being chased, beaten and pepper-sprayed.

Organizers of Saturday’s event, initially scheduled for Crissy Field, called it off after the National Park Service put in sweeping security measures. In the end, a handful of members of the right-wing group turned up at Crissy Field.

The violence in Berkeley is under investigation. Coats asked people who had been in the crowd to report any injuries and to submit video. She said the Police Department is is creating a special website for people to submit video.

Chronicle staff writer Michael Cabanatuan contributed to this report.

Lizzie Johnson, Erin Allday and Evan Sernoffsky are San Francisco Chronicle staff writers. Email: ljohnson@sfchronicle.com, eallday@sfchronicle.com, esernoffsky@sfchronicle.com Twitter: @LizzieJohnsonnn, @ErinAllday, @EvanSernoffsky