But others, at least for that day, kept aggressive people like that man in check. Some joined the protest with signs identifying themselves as medics to help the hurt, and many volunteers showed up in cars to pass out cold water bottles, snacks, and hot pizza. 

Others designated themselves peacekeepers for the day, such as Santana Lopez, 25, who urged people to “keep the peace” and “resist the urge.” The weekend’s looters angered her: “From what I’ve seen, it was usually Caucasians starting the breaking, and I think they’re trying to influence us into violence. They’re causing damage, and then people are blaming us.”

The aggression provoked police, and many protesters got hurt in the crossfire. Lopez had been in Fairfax District in Los Angeles Saturday protesting when police officers fired tear gas and rubber bullets to disperse the crowds. She lifted her shirt to show me a big bruise on her lower back: “I got shot yesterday for saving someone who got shot in the head.” 

Others tried to be peacemakers too. When one man whipped a spray paint can out of his duffle bag and vandalized a public bench, Ricky Woznichak and his friend John Snyder, both 38, admonished him: “Hey! Stop vandalizing!” They made up later with an elbow bump.

“This is not a good look,” Woznichak told me, regarding the vandalism. “I don’t want the wrong people getting blamed.” He and Snyder were both at the protest the day before too, and they left as soon as the police began firing tear gas, which burned their eyes and throats. Snyder showed me the mark on his jeans where a rubber bullet struck his shin. But they were back on the streets again on Sunday with their signs. “We gotta stand up for what we believe in,” Snyder said.

But they too are wary of people they call “plants” and “instigators.” Most protesters Saturday, they said, were peaceful and approached the police with their hands up. But a few had jumped out, thrown something at the police, and ran back to hide behind the peaceful protesters. “We’re not those people so we don’t know [who they are],” Woznichak said. When I asked if they knew who the organizers of these protests are, they both shrugged. “The internet?” Woznichak said. “Who knows?”

By the time the protesters walked a roundabout route and crossed Grand Park to reach city hall, a few black men designated themselves as the leaders by standing between the officers guarding the building and the protesters across the street. One older man lifted a loudspeaker and reminded the group, “We do not want anyone rioting or looting!” Another younger man took the loudspeaker and declared, “We cannot escalate the violence! We cannot give them any more reason to shoot and kill us!”

Then the leaders asked people to kneel and observe a moment of silence for black people who have died from injustice and police brutality. Hundreds dropped to their knees like a rippling wave. For a few minutes, the entire area went silent except for the whirling, choppy swooshes of police helicopters circling above. 

It was almost 5:30 p.m. At once, phones in people’s pockets began buzzing, and emergency alert tones sounded: A countywide curfew was going into effect at 6 p.m. Then the separation started. Some would go back home to observe the curfew, and others would stay against orders. 

One of the leaders lifted the loudspeaker again and begged the protesters: “Do not burn our city down. Do not harm one another. This is not black or white. This is the people against injustice and violence!” The crowd cheered in agreement, and most of them trudged back to their cars.

Somber news came that evening: Hundreds of looters punched and kicked down the boards covering stores in Santa Monica and Long Beach. They cheered when the plywood broke and windows shattered. Streams of people rushed into the stores and waddled out with arms full of goods: boxes of designer shoes, bicycles, surfboards. 

Some had clearly prepared for the occasion: SUVs and trucks pulled up in front of the store while looters heaved items inside and dashed in for more. The Santa Monica Police Department said officers arrested about 400 people that day, 95 percent of them from outside the city. In downtown, one Latino man in his 20s died from a gunshot from an unknown person. It’s still not clear if the murder was related to the protests. 

More looting followed more protests Monday. Police seemed to be quicker in stopping it, but Los Angeles County was under mandatory curfew for the third straight day.

Lopez, the peacekeeper at Sunday’s protest, said the rioters and looters are missing the point: “They’re out here angry and letting out that violence, but we’re not out here to start violence. If things start getting ugly … I’m going to loud, I’m going to tell them not to because this is our protest. It’s not OK for them to take that away from us.”