MINNEAPOLIS — Night after night, tear gas has hung like a cloud over the Sterling Square Apartments, just across the street from the Brooklyn Center Police Department, seeping through the walls and air vents like an invisible predator.

The two-story apartment complex has been ground zero for demonstrations over the April 11 fatal shooting of 20-year-old Daunte Wright by a Brooklyn Center police officer. Residents have looked outside their windows as protesters clash with law enforcement officers who have used the chemical irritant as well as stun grenades and other less-lethal weapons to control the demonstrators.

The aggressive tactics have injured dozens of protesters and journalists and sent dangerous fumes and projectiles into the adjacent apartments, leaving residents sick and fearful in what many describe as a war zone. The tenants, many of them low-income and Black, have reported rashes and nosebleeds and say they are unable to sleep because of the fumes and noise.

“We have been sneezing and coughing every day, because it comes through the walls and then it stays in the walls,” said Iranesha Anderson, 29, who has four children, two of whom have asthma. “You can’t even air out your apartment, because the s--- still keeps coming in.”

Protests continued outside the Brooklyn Center Police Department headquarters in Brooklyn Center, Minn., for a fourth night over the killing of Daunte Wright. (Mark Brown, James Cornsilk/The Washington Post)

The law enforcement response to the protests over Wright’s killing has elevated tensions in neighboring Minneapolis, a city already on edge as it braces for a verdict in the murder trial of Derek Chauvin, the former police officer accused of killing George Floyd.

Two Minnesota National Guard members were injured when someone fired on a security team made up of troops and the Minneapolis Police Department in a drive-by shooting early Sunday. There were no serious injuries, according to the Guard’s leader, Maj. Gen. Shawn Manke, but he said the incident “highlights the volatility and tension in our communities right now.”

There were protests against police shootings in several U.S. cities over the weekend, including in Portland, Ore.; Chicago; Oakland, Calif.; and D.C., where four people were arrested in clashes with police as a march was wrapping up.

Closing arguments are scheduled for Monday in the landmark case, and officials, business owners and residents across the city are afraid Minneapolis could see a repeat of the civil unrest that erupted after Floyd’s death last May.

The killing of Wright, an unarmed Black man who was shot by a police officer during a traffic stop April 11, has not only increased anxiety over the potential for violent protests and looting, but it has also created confusion over who is in charge of efforts to keep the city safe. Minnesota Gov. Tim Walz (D), Minneapolis Mayor Jacob Frey (D), the city police chief and the county sheriff all share in the role, but they appear to hold different views on how best to respond.

“It just feels like it’s more politically driven than productively saying, ‘What can we do to prevent people from getting harmed here?’ ” said Lonnie McQuirter, 35, owner of 36 Lyn Refuel Station in Minneapolis, who, like many residents, is torn between needing police to protect his business and being concerned that an overly aggressive response will do more harm.

Last week, thousands of Minnesota National Guard troops began deploying throughout the city, taking up armed positions along commercial corridors and in residential neighborhoods alongside police officers as part of what city and state officials describe as a deterrent to potential looting and violence in response to the Chauvin verdict.

The unprecedented level of security includes more than 3,000 National Guard troops and at least 1,100 officers from public safety agencies across the state as part of a joint effort known as Operation Safety Net. The massive show of force, officials say, is aimed at preventing a repeat of the violence that erupted across the city last summer, including the burning of a police station and an estimated $350 million in damage to buildings and businesses.

But the wartime posture has alarmed some residents and elected officials who have repeatedly complained in recent weeks that the heavily militarized approach ignores the community’s trauma over the events of last summer, when mostly peaceful protesters were tear-gassed and injured by police action. Many elected officials think that aggressive response resulted in the subsequent violence and destruction, lessons that some believe were ignored in Brooklyn Center.

Last week, Brooklyn Center Mayor Mike Elliott and the city council called on law enforcement to dial back their response, including their use of chemical irritants.

“We have to approach policing in a different way, in a more humane way,” Elliott said. He and others also criticized the mass arrests of mostly peaceful protesters, including 136 people on Friday night.

On April 15, Katie and Aubrey Wright spoke about their son Daunte, who was killed by a police officer during a traffic stop on April 11. (Reuters)

But state and regional public safety officials — who responded to the scene in Brooklyn Center as part of Operation Safety Net — have steadfastly refused to change their tactics, saying they are needed to maintain “peace and safety” in the region.

In a letter to Elliott, Hennepin County Sheriff Dave Hutchinson, one of the leaders of Operation Safety Net, accused the mayor of causing “significant confusion” by questioning police procedures and asked if the city no longer wanted help.

Many viewed Hutchinson’s comment as an implicit threat, including Minneapolis City Council members who publicly complained about the tactics used in Brooklyn Center and expressed concerns that they could be a preview of what’s to come in Minneapolis in response to the Chauvin verdict.

On Friday, the Minneapolis City Council voted 11 to 1 in favor of a resolution calling on police to stop using tear gas, rubber bullets and less-lethal weapons to disperse crowds in Minneapolis, but because the administration of the police department falls under the mayor’s power, it was merely a “values statement,” as some members put it.

“We have seen a version of what the Operation Safety Net tool kit is and what [its] approach is, and I think it’s very important that we speak out now to say this is not what we want in our city,” said council member Steve Fletcher, whose district includes downtown Minneapolis. “This is not something that represents Minneapolis values. This is not the way we want to be responding to protesters. This is not the way we want to be responding to crowds of people in our city.”

Hutchinson and Frey did not respond to requests for comment. But Frey said in a briefing last week that his priority was the “safety and security” of the city and its residents and called for unity.

“This is a hard time for our city,” Frey said at the briefing. “These times are tense. They are traumatic, and they’re going to need all of us working together in every respect.”

Last summer, in response to criticism about the police response to protests, Minneapolis Police Chief Medaria Arradondo announced a change in department rules that prohibits his officers from using pepper spray, tear gas or other less-lethal weapons without his authorization or that of someone he designates.

In the run-up to the Chauvin trial, Arradondo, the city’s first Black police chief, said the department had learned from and had conversations about the anger that fueled last year’s protests and said officers had been further trained in de-escalation measures.

Minneapolis City Council members pointed to the refusal of sheriff’s deputies to comply with Brooklyn Center requests to cease the use of tear gas and other aggressive tactics and questioned who will ultimately be in charge of making that call in their city.

On Thursday, Arradondo reiterated that he will have operational control over all law enforcement flooding into the city and that he, in consultation with other leaders of the joint operation, would decide on the tactics used.

“Ultimately, in our jurisdiction, it would be my call,” Arradondo said in a briefing on the city’s security plans related to Chauvin’s trial.

But, adding to the confusion over who is in control, Arradondo later added that other “mutual aid” partners wouldn’t necessarily have to abide by Minneapolis police policy, including on the use of munitions.

“They’re aware of the criteria that I have to have on the ground here in Minneapolis,” Arradondo said. “They still have to have their own policies that they have to abide by. There’s still laws and regulations that they have to abide by. But we’re working in concert with each other. And so that communication, I think, is key in making sure that we can do things safely and in peace and keep our communities safe and peaceful.”

Walz, who has command of the state’s National Guard, has come under intense criticism in recent days for supporting the aggressive show of force surrounding both the trial and Brooklyn Center.

At a Thursday news conference, Walz told reporters he was “deeply concerned” by the use of tear gas on protesters in Brooklyn Center and how it had affected residents. But he called the tactics necessary for preventing destructive unrest.

“One of the things that I learned in May is that as an elected official, you can’t sit away from this and put people out there whose lives are in danger and not allow them to make some of those decisions,” Walz said. “What do you think would have happened Sunday night or Monday night, especially had there not been a fence there and had there been no one there,” he said, referring to the fortification of the Brooklyn Center police station after Wright’s killing. “I’ve learned from the past that building would have been burned down, and my fear was that the surrounding apartments would have burned, too.”

But Minneapolis City Council member Jeremiah Ellison, whose father, Attorney General Keith Ellison, is leading the prosecution of Chauvin, accused Walz and other political leaders involved in trial security efforts of leading “by fear.”

He accused law enforcement of misusing less-lethal weapons and using force when it was unnecessary, pointing to several pending lawsuits against the city filed by residents and journalists who were injured by police projectiles during last year’s unrest. A recent University of Minnesota study found that more than half of the 89 people treated for injuries during last year’s protests in the Twin Cities were hurt by projectiles that are considered nonlethal, including rubber bullets and tear gas canisters. Sixteen suffered traumatic brain injuries; 10 had eye injuries.

“The use of these weapons have never resulted in people peacefully retreating and going home,” said council member Ellison. “They’ve always sort of bubbled into more chaotic situations, and they’ve always created a situation, always created the atmosphere for folks to be either enraged and to express that rage on the property.”

The security preparations have added to the feeling of a militarized city. The Hennepin County Government Center, where Chauvin’s trial is being held, and adjacent buildings have been fortified with concrete barricades and multiple layers of high-security fencing topped by barbed wire.

Other buildings across the city also have been secured with concrete, fencing and plywood, including police stations and other public buildings. On Friday, the sounds of power tools echoed throughout the mostly empty streets of downtown, where workers were seen erecting a large fence around a post office and adding a wooden barricade to a hotel that had been boarded up weeks earlier.

Minneapolis Public Schools, which only recently resumed in-person teaching because of the coronavirus pandemic, announced it would return to remote learning beginning Wednesday in anticipation of the verdict.

The increased security response has drawn mixed reactions across the city, including in areas that are still recovering from last year’s destruction.

Over the weekend, in the city’s Lyn-Lake neighborhood, which is packed with restaurants and retail stores, National Guard troops stood on street corners with their M4 rifles, while others sat in Humvees. They were positioned near boarded-up businesses where some of the plywood had been painted with messages of justice, including one that read “Black Lives Matter All Year Round.”

The neighborhood was hit hard by several consecutive nights of rioting during last year’s protests. Then, on the night of Wright’s killing, looters and vandals hit some businesses again in what Minneapolis officials described as coordinated crimes planned in advance by those seeking to take advantage of the renewed unrest.

However, store owners and managers remain divided over the increasing law enforcement and military presence, and they question whether state and local officials truly have a clear plan for heading off problems in the days and potentially weeks ahead. Some have invested heavily in protecting their rebuilt businesses, including on metal gates. Some business owners have hired private security firms, despite it costing as much as $3,000 a day.

Last year, looters caused hundreds of thousands of dollars in damage at Anthony’s Pipe & Cigar Lounge, where customers crowd into a dark, century-old wood-frame building to smoke fine tobacco. The vandals smashed glass-enclosed rooms and humidors, stealing or destroying thousands of cigars.

General Manager Tom Harlan said he and other merchants in the neighborhood felt abandoned during the protests last year, with police officers even telling him at the time, “You are on your own.”

So this year, Harlan boarded up early. And he views the National Guard’s presence as a sign that local and state leaders are being proactive.

“Just by having them out there, [looters] are going to think twice,” said Harlan, adding that he also feels more secure that Hutchinson, the sheriff, appears to be taking more of a leadership role. “At least there is one guy that is taking responsibility, because I don’t suspect our mayor is going to do anything.”

But other Lyn-Lake retailers said they still feel vulnerable because of poor communication and uncertainty over who is really in charge.

“No one has contacted us directly, and all the information we have we got by searching on our own,” said Johnny Gayzmonic, assistant manager of Eye of Horus, which sells metaphysical and meditation products. “That was the case last summer, too. . . . I just wish the city would communicate better with us, because it would be nice to know they are looking out for us.”

Some retailers are opposed to the preemptive deployment of National Guard troops.

Esai Luna, manager at Legacy Glassworks, which sells colorful glass smoking pipes, said the image of armed soldiers standing near his store only heightens tensions. Luna, 23, said he also worries that relatively low-crime communities such as Lyn-Lake are receiving more law enforcement resources than poorer, predominantly Black neighborhood retail districts.

“The root issue of all this is the police themselves,” Luna said. “So to have them in your face even more is the last thing anyone wants. . . . What people want is for them to be out of the way, minding their own business, where they can’t f---ing hurt people.”

Others want more.

Mohamed Keynan, who owns a clothing business in the predominantly Somali American neighborhood of Cedar-Riverside, recalled how he tried to call 911 for help during last year’s riots, only to be told the city “had bigger problems to deal with,” forcing him and other business owners to guard their properties around-the-clock.

Keynan initially was disheartened last week when he saw National Guard troops in predominantly White commercial districts. But his dismay turned to relief when soldiers arrived in Cedar-Riverside on Friday — a repositioning that came after a city council member complained that the area had been overlooked. Armed troops walked the neighborhood, occasionally popping into stores to greet people who were fasting as part of the month-long observation of Ramadan. Other soldiers hung out in Humvees, with armored vehicles parked nearby.

“When I see the police and when I see the military, I feel comfortable,” said Keynan, as two troops in combat fatigues walked past his store. “I at least feel like they will protect our neighborhood.”

But Keynan said local business owners are still terrified that the Chauvin verdict could trigger the “worst” violence yet in the Twin Cities region. He and others are not convinced that troops will stick around, leaving merchants on their own again.

“If [Chauvin] gets off, everything will be upside down,” Keynan said, adding that the Somali American community also fears possible retaliation from far-right extremist groups, should the ex-officer be convicted. “Everyone is very nervous, because we just don’t know what is going to be happening.”