On Aug. 21, 2018, beginning at 5:29 p.m., Tamar Manasseh streamed live smartphone video to Facebook from the corner of 75th and Stewart in her Englewood neighborhood on Chicago’s South Side. She narrates 20 minutes of a “police chase on the block,” saying, a police officer has “his gun out, and he’s chasing somebody. … Here come some more. They got guns out, and they’re chasing somebody. … If you’re chasing somebody with a gun, what happens when you catch him?”

Nobody answers her question, so she answers it herself: “Oh, they shoot themselves in the back of the head. I forgot.”

A crowd gathers and grows, watching, as the police presence likewise gathers and grows. “They really mad,” Manasseh assesses the mood of the police. “They got the chopper out!”

Everybody’s got questions. Manasseh’s got questions.

“So, I’m just wondering what they’re down here for. Because I’ve heard no gunshots. I haven’t heard anything. … Is this what it looks like in your neighborhood when there’s no shots fired?”

Maybe the officers were looking for a dangerous person posing an imminent threat to the community. Maybe they were apprehending a suspect wanted for harming someone the residents knew or loved.

Manasseh notes various “white shirts,” a neighborhood term for lieutenants, sergeants and the like, but none of them approaches the onlookers. Likewise, no one in the crowd on the corner flags down a patrol vehicle or foot officer, if that is even possible. Why would they? With the squad cars, helicopters, guns and sheer numbers, the police resemble an invading army.

We’ve all seen this before. Time and again, we’ve seen what happens when the police and the communities they are sworn to serve and protect do not communicate or trust one another.

In the early 1980s, I was an officer in the Miami-Dade Police Department. It was there I was introduced to a concept we now call “community policing.” It was so radically new it didn’t even have a name. Back then, policing in urban Florida was all about runnin’ and gunnin’, kickin’ ass and takin’ names. But Major Doug Hughes, the commanding officer of Central Precinct, was determined to build relationships with people not just on the neighborhood streets, but in places like the James E. Scott Homes, a grim, low-rise subsidized housing development that had become shorthand for drugs, gangs, intimidation and murder.

Hughes wanted us to treat the Scott Homes like a neighborhood. It was no easy command. There really were some dangerous people living there. But we soon learned that most of the residents were folks who just wanted to raise their families in peace and safety. When we proved to them that we were there to help, they reached out to us in return.

Fast forward to 2015. As a member of President Obama’s Task Force on 21st-Century Policing, I listened when Camden County, New Jersey, Police Chief J. Scott Thomson explained that “community policing starts on the street corner, with respectful interaction between a police officer and a local resident.”

That interaction is missing from Manasseh’s video.

In Englewood, Manasseh does the kind of outreach the Chicago Police Department should be doing. For her, it began after the June 2015 shooting of 34-year-old Lucille Barnes on the corner where Manasseh later shot the video. Barnes was killed and two other women wounded. Manasseh didn’t know Barnes, but she was moved to do something. That was to start MASK, or Mothers Against Senseless Killings. She recruited others into her “Army of Moms,” who “spend hours sitting on the corner of 75th Street and South Stewart Avenue chatting to passers-by and offering them barbecue,” she told the Jewish Telegraphic Agency wire service. “If I didn’t do something, it would come for my kids eventually,” she said. To Chicago Magazine, she added that the bearing witness, the sharing food, and the talking “have been enough to stop gun violence there.”

Really? The statistics back her up. The corner, in the middle of a violent neighborhood, saw zero shootings in 2016, according to the JTA article, and this year, the Chicago Tribune reported that gun-related incidents continued to decline in the area.

So what was happening in the police encounter caught in Manasseh’s video? I called Glen Brooks, the C.P.D.’s director of Public Engagement. He got back to me and explained it began when officers spotted a vehicle involved in a shooting. A flash message was sent to all cars. Officers went to stop the vehicle and the subjects threw a weapon out of the window. A subject was subsequently apprehended.

Brooks also said the department is acquainted with Manasseh, who has received national attention for her anti-violence efforts, and that they’ve been planning to meet with her. As of September, they hadn’t, due to “scheduling conflicts.” In a message relayed through her rabbi, Manasseh said police still have not told her the reason for the commotion she recorded.

I’m not sure they told me, either. The date Brooks gave for the encounter he described was Aug. 30, not Aug. 21, the date of the video that I asked about. Brooks did not return two follow-up fact-checking calls from an editor at The Marshall Project.

Whatever the date, if indeed it was about a bad guy misusing a gun, I’m glad they got their man (or woman). But I would have hoped they could have done so without traumatizing a neighborhood, let alone squandering the potential resource of neighbors who could have helped facilitate a far more peaceful apprehension.

A personal note: In 2016, I was a finalist in Chicago’s search for a new police superintendent. I am not here to second-guess their leadership in 2018. Indeed, runnin’ and gunnin’ without stopping to talk is hardly police behavior indigenous to Chicago.

But, based on the stats—more than 600 murders and 2,800 shootings in the city so far this year, and zero on the corner of 75th and Stewart since Manasseh and others began sitting there—I am convinced there is a better approach. And a community that should be embraced, not ignored by police racing off to apprehend someone.

Cedric Alexander’s 40 years in law enforcement includes chief of police positions in Rochester, New York, and DeKalb County, Georgia. He served as federal security director for the Transportation Security Administration and was a member of President Obama’s Task Force on 21st-Century Policing. A past president of the National Organization of Black Law Enforcement Executives, Alexander is currently deputy mayor of Rochester. He may be reached at Acopdoc@aol.com