A few weeks ago, when the news was about Debra Harrell, a black single mom who left her 9-year-old daughter at the park for the day while she went to work at McDonald’s, I talked on the Slate Political Gabfest about why I’m reluctant to call the police, especially on black people. The day that show taped, Eric Garner, a 43-year-old unarmed black man, got into an argument with the police in Staten Island and was killed when one officer put him into a chokehold. The video of this incident, shot by a friend of Garner’s from the street, shows a shockingly swift escalation from Garner’s words to the cop’s violence. As I got tweets and emails from Gabfest listeners flagging it for me, I had that sick feeling you get when something awful happens that proves your point.

It was just one anecdote, just coincidence. Except of course, it wasn’t. Last Saturday, police in the St. Louis suburb of Ferguson, Missouri, killed 18-year-old Michael Brown, who was black and unarmed. Police Chief Thomas Jackson says Brown hit an officer and tried to take his gun; on Thursday, Jackson added that the officer had gone to the hospital and that his face was swollen. The friend Brown was with, Dorian Johnson, tells a different story. Johnson says he and Brown were walking down the middle of the street when a police officer told them to get on the sidewalk, and that Brown used only words, not his fists, to object. Another witness said she saw Brown tussling with an officer at the window of a police car, and that Brown fled as shots were fired.

Maybe we will find out who is telling the truth about Michael Brown’s death, and who is not, but it’s hard to have faith in that right now, as the St. Louis County Police Department, which is investigating the shooting, turns Ferguson into a military zone. The images and descriptions of cops in riot gear, training huge guns on protesters and shooting tear gas and rubber bullets into peaceful crowds, are just unreal. Or at least, they should be. I know there was looting in Ferguson over the weekend, but now, as my colleague Jamelle Bouie points out, it’s the police who are jacking up the conflict, with their armored vehicles and gas masks and SWAT gear (courtesy of the federal government). Instead of calm, they are bringing chaos, refusing to release the name of the officer who shot Brown and last night, arresting two journalists.

Meanwhile, black people across the country are responding with moving images in the Twitter feed #iftheygunnedmedown, and showing solidarity, soberingly expressed in this photo from Howard University. Black writers like Jamelle and Jelani Cobb are explaining why Brown’s death resonates, adding it to a list of other suspect police shootings and explaining how, as Cobb put it, “the race-tinged death story has become a genre itself, the details plugged into a grim template of social conflict.”

I’ve been thinking about something related but different: Why writing about legal issues for 20 years has taught me that black people are at risk from the police in a way that the rest of us are not—and how that shapes my own choices.

Maybe the unfairness I’m talking about is obvious to you, whatever your race. There is plenty of evidence that black men, in particular, bear the brunt of arrests, convictions, and long sentences, out of proportion to their crime rate. The divide opens early in life: Black kids are far more likely to be suspended, expelled, and funneled into the juvenile justice system than nonblack kids. Again, the disparity can’t be explained by their behavior: It reflects the heavy hand of systemic bias. There are incredibly depressing studies suggesting that “racial bias also factors into officers’ split-second decision to shoot a suspect,” as Rebecca Leber lays out in the New Republic. It does not help that police officers tend to be white more than the communities they serve (especially outside of large cities). In Ferguson, for example, two-thirds of the residents are black, and 50 of 53 police officers are white.

In covering the law, I’ve had more chances than I want to remember to watch these patterns play out in people’s lives. It’s become pretty much a given for me that if the criminal justice system gets a hold of a black person, especially if he is poor, there is a terrible, heightened risk that it will try to crush him. I know we need law enforcement. I know most cops are good people who are trying to do their jobs. But the police have so much power. And often, they are not made to answer when they abuse it—even when, as it appears in Garner’s case, they broke their own rules.

But I don’t just know this because of my job. I’ve known it since childhood, because I grew up in Philadelphia, and I’m old enough to remember the frightening, overt racism of Frank Rizzo’s police department and the sorrowful night in 1985 when a black neighborhood burned. Rizzo was gone by then, and we had a black mayor, but the long-running conflict between the police and the black liberation group MOVE helped give rise to that fire, which killed 11 people and burned down 61 homes.

You might say, that’s a crazy extreme, and it happened a long time ago. (Or you might have, until you saw Ferguson last night.) Here’s a memory of an incident that’s far more ordinary but for me more indelible, because I didn’t see it refracted through a TV screen. It’s from 1998 or 1999, just across the border of New Haven, where I lived, in the town of Hamden, on a street called Cherry Ann. I was visiting a black family, four sisters and a mother. Bear with me while I explain what I was doing there. I met this family in 1993, when I was an intern at the New Haven Advocate. I was supposed to write about them as an example of successful reunification after foster care. It turned out that the story was more complicated than that. The girls were the victims of prolonged and serious sexual abuse at the hands of the father of the youngest one, who had lived with them and their mother. When I met them, his trial was a month away and the two oldest sisters were to be the main witnesses. They were 11 and 13. I spent the summer reporting their story, which mostly meant hanging out with them on their front porch, going to the park, and swimming at the public pool. The prosecutor in the case was dedicated, caring, and full of concern for them. The girls gave their testimony, credible and solid, and the man who hurt them went to prison for a long, long time. That part of the story is about the criminal justice system working.

But on the late ’90s night when I stopped by to say hello, I saw a side of law enforcement I’d never seen firsthand. I was inside the house, talking with the girls and their mom when we heard sirens come screaming down the street. We looked through the window and then opened the front door. The cops pounded on the door of another home on the block. They went inside and came out with two guys who they clubbed to the ground. When the men were down, faces against the asphalt and hands cuffed, the cops yanked them into a police car and went zooming off into the night.

I don’t know who those men were or what they’d done. I asked the girls and their mother if they were drug dealers, and they shook their heads: They didn’t think so, but they didn’t know. Mostly, they weren’t surprised. Whatever led up to that arrest, to them the use of force felt routine. Like everyone else on the street, they went back inside and shut the door.

For me, the whole thing was mind bending. It all seemed entirely unaccountable. This was before cellphones and the citizen videos that have changed how we see deaths like Garner’s or an arrest of a black passerby like this one. I had no idea what to make of what I’d seen. Were the police protecting people like the family I was visiting from the thugs in the neighborhood? Or were they flexing their muscle because they could? Had they crossed the line into misconduct? Were they a force for good or for ill?

I still don’t know. But I came away sure of one thing: I couldn’t imagine anything like that happening on any street I’ve lived on. And it’s black people who tend to live in the places where it does happen—and when the police clearly do use excessive force, their victims often have little recourse. And sometimes, people die. That happened again on Monday night, in Los Angeles, to 25-year-old black man Ezell Ford, whose mental illness, his family said, was well known to the police but who the police say got into a struggle during an investigative stop, went for an officer’s gun, and was shot and killed.

Between 2003 and 2009, according to the Bureau of Justice Statistics, 4,813 people died “while law enforcement personnel were attempting to arrest or restrain them, or shortly thereafter,” as Gene Demby writes for NPR, and about 60 percent of the deaths are classified as homicides by the police (I don’t know how many of the people killed were black). Demby points out that this is a small number in the context of the 98 million arrests made nationally during the same time period. But it’s still a scary number, especially when, as in Michael Brown’s case so far, police departments seem intent on protecting their own from the consequences.

This is the sharp edge of my explanation for why as a white person, if I have a choice about whether to involve the police in the life of a black person, I will try to choose not to. I’m not saying that I won’t call 911 and pray as hard as I can for the police to come if someone, whatever race, breaks in to my house. But much of the time, our choices are made in a far hazier gray area. To go back to the story of Debra Harrell and her daughter, who wound up respectively, getting arrested and going into foster care: If I saw a 9-year-old black girl alone in the park, and she said her mom was at work, I would not call the police. I would ask that girl if she was OK and try to talk to her mom. Because, once the wheels of the bureaucratic state start to turn, they can grind people up. Maybe the police want to help but don’t have discretion. Maybe “the law is an ass,” as my colleague David Plotz put it on the Gabfest. Whatever the cause, I would rather stay away from bringing its weight to bear on someone else, especially when I know that person is likelier to get an unfair shake.

The girls whom I visited on Cherry Ann Street have grown up, and one of them has an 18-year-old son. He graduated from high school in May, and he’s supposed to start college next week. He is a good kid who has not had an easy life and who is making his way. One day earlier this summer, he says, a friend brought a moped to his house and said he could ride it. The boy I know drove the bike and got stopped by the police because he wasn’t wearing goggles. They ran the moped through the system and discovered it was stolen, and he’s now facing larceny charges. This wouldn’t happen to one of my sons. I just don’t think it would. Just like I don’t think I would ever have my kids taken away from me for letting them go to the park alone.

So what does this have to do with Ferguson? What’s happening there—the tear gas, the tanks—is not what’s happening in black neighborhoods all across America every day. But it’s the same dynamic that black people experience too often, and more often than everyone else: The arm of the government that is meant to protect them instead poses a danger, to their lives and their futures. Keep that in mind the next time you consider calling the cops.

Read the rest of Slate’s coverage of the protests in Ferguson, Missouri.