SEATTLE — Antonio Ochoa has no formal security training. But around 3 a.m. on recent Saturday, they were called to help defuse the situation unfolding on a street corner. A man had been yelling, and he began punctuating his anger by knocking over a metal trash can.

Ochoa, who is white and uses they/them pronouns, did not engage the man, who is black, directly. Instead, they began picking up trash, while giving the man space. He quickly turned apologetic and offered to help clean up.

For the past several days, Ochoa, 28, has been serving as an unarmed volunteer “sentinel,” or guard, in the protest zone. Ochoa, a self-described leftist libertarian recently furloughed from the Seattle International Film Festival, and other volunteers have been serving four-hour shifts to help to keep the peace.

The zone was formed last week amid the Black Lives Matter protests. Activists had gathered at a neighborhood police precinct to call for accountability and an end to police violence. In response, on June 8, police officers left that area. A spontaneous protest encampment has since sprung up outside the building, run by volunteer activists.

Core to the zone is a vision of a self-governed community with no formal policing. Instead, volunteers, many of them avowed police abolitionists, have begun to organize their own safety force.

Among other incidents, these volunteers have confronted a man throwing apples and threatening punches, a car driving toward a large crowd of pedestrians and a vehicle circling the block repeatedly and taking photos. Volunteers say they have engaged with armed visitors from outside the city who came to the zone convinced that Seattle needed saving from left-wing agitators.

They have defused fights, protected store windows from vandals and handled mental-health crises. Protesters rushed to douse the flames when a lone arsonist attempted to set fire to the precinct early Friday. The director of an LGBTQ resource center publicly thanked sentinels from the protest zone Sunday for their assistance watching over a broken window until plywood arrived, attributing the incident to a mental-health or drug-addiction issue with a person who regularly sleeps in the center’s doorway.

Volunteers say this work is a way to highlight what a city without police might look like. “We have a chance to really build something here, so I have a vested interest in defending that as a part of my community,” said Ochoa, who lives in the city’s Capitol Hill neighborhood. “I live on the Hill, and the police presence here has always been tense and kind of malicious.”

Over the weekend, about two dozen people served as sentinels, provided the micro-neighborhood with a round-the-clock security presence. From a folding table under a pop-up tent on the sidewalk, a volunteer coordinated schedules on a whiteboard and notepad.

On Sunday, a half-dozen people inquired about signing up, including several women of color. The coordinators paired volunteers to establish a buddy system, handed out radios for on-site communication and added phone numbers to a group chat on the encrypted text service Signal.

They offered basic tips in de-escalation: Speak in a low volume, establish a dialogue, use slow hand movements to communicate that the situation is calm, alert offenders that they are being watched.

That was the approach a pair of volunteers took with a man throwing apples at passersby. Ochoa and others watched him carefully, while assuring him that their intention was not to hurt him. He punched one of the sentinels, who did not retaliate. Eventually, the man calmed down and left.

“These alternatives that don’t involve forcing someone to the ground and immediately handcuffing them work and provide for a much safer community in general,” Ochoa said.

Listening and trying to understand the needs of those who are in an altered mental state — whether drunk, high or struggling with mental illness — is essential to the approach.

A sentinel who goes by the name Mark Markinson said addressing conflict in this way helped him calm a person threatening punches, by offering him a slice of pizza. It turned out he was hungry. “I don’t walk up to any situation assuming that I know who’s wrong,” said Markinson, dressed in black and sporting a cap with the trans pride flag superimposed with a rifle decal and the phrase “Defend Equality.”

Markinson describes himself as an anti-fascist, anti-racist community defense advocate. He is a gun owner, but he was unarmed Saturday night. He was serving at the occupation’s southernmost barricade, where eight people practiced pushing aside three metal jersey barriers and three empty plastic water wells to open the barricade’s proverbial gate for local residents and business owners. They had the routine down to 12 seconds.

“The person yelling isn’t necessarily wrong,” Markinson said. “Ultimately, maybe nobody is wrong. You just have to listen to who is in the argument and de-escalate and mediate, possibly try to get those individuals not to be around each other.”

“You just can’t go into that situation with any preconceived notion about who might be causing a problem,” he said. “Often I feel like police officers go into those situations with a lot of preconceived notions.”

Markinson, who is white, said he struggles with his own implicit bias in the face of a culture that ingrains an irrational fear of darker-skinned people. “That’s something I’ve actively tried to combat for a very long time,” he said. “It’s important to make sure that you’re aware that it’s there and try to learn as much as you can about other people. Diversify your friend group and who you hang out with.”

Markinson views Seattle’s ongoing experiment as part of a lineage of anarchist neighborhoods such as Exarcheia in Athens, Rojava in northeastern Syria and Free Christiana in Copenhagen. Ochoa draws comparisons to the National Confederation of Labor, which arose during the Spanish Civil War, as well as the small U.S. towns that have eliminated their police departments in favor of neighborhood watches.

The model does have its challenges. On Saturday, dozens of people surrounded a fire-and-brimstone street preacher who regularly disrupts local protests with in-your-face threats of eternal damnation.

When efforts to escort him out peacefully failed, someone dragged him on the ground. One person briefly put him in a chokehold while others blocked attempts to film the incident with their phones. Later that afternoon, a couple dozen people marched up to the precinct with U.S. flags held aloft. A crowd gathered around them, and one of the flags was confiscated.

Firearms present a different challenge. Many of the volunteers are licensed gun owners, but bringing a weapon changes the dynamic. “If you are open-carrying, de-escalation is more challenging because at that point you are also a threat to anyone that you come up to,” Markinson said.

But that can leave volunteers vulnerable. Sentinels say they are particularly concerned about right-wing groups such as the far-right Three Percenters and the Proud Boys, a group that has made headlines for its part in violent clashes in Portland, Ore., and New York.

An uneasy compromise could be seen early Sunday, when a sentinel who gave his name as James Madison stood at the southern barricade with an AR-15 draped over his chest, as he has done on other nights.

Madison said he was standing guard because of reports of a “known threatening vehicle” circling near the autonomous zone. “We found the owner of that threatening vehicle’s Twitter, and he clearly intended to do harm to the protesters based on his tweets,” he said in a text message. “There are a few of us who are armed.”

At the much quieter eastern barricade, Ochoa found that volunteering connects them with the neighborhood in a way they have found lacking. “U.S. culture is extremely atomizing, especially in terms of how suburban neighborhoods and apartment buildings work,” they said. “The sense of community that I grew up with in a smaller town is completely dissolved as I move into a city, so having community involvement like a neighborhood watch or a rotating council of people making decisions is something I think needs to happen for any sort of brighter future in the United States.”

As this experiment evolves, a hand-painted sign approaching the barricades offers watchwords: “In a world without cops we must never again become the cops ourselves.”