The shootings of Alton Sterling and Philando Castile are horrifying to the black community – horrifying, but unfortunately not surprising. Or new. The only thing new is that in this age of cellphones, everyone is a “citizen journalist” and this incident was recorded.

There’s one thing about the violence being suffered by black people at the hands of police that many white people can’t – or won’t – understand: If a young black man is standing alone on a street corner late at night waiting for a bus and a police cruiser slowly approaches, he’s afraid. He knows he’s being checked out and there’s a possibility he’ll be hassled, or worse, even if he’s completely innocent. A young white man in the same circumstance feels safe. “Whew,” he’s thinking. “This neighborhood’s kind of sketchy; I’m glad to see cops around.” Black men (and of course women too, though usually in different circumstances) often experience the police as an army of occupation, an young white men usually see them as protectors. That’s the simple reality, despite the “All Lives Matter” blather born of either ignorance or cynicism.

Obviously we need better screened and trained police. But as I suggested after Michael Brown was killed in Ferguson, Mo., that won’t happen until we have civilian police review boards with actual power that aren’t part of the police culture. Creating such boards would mean going to war with police unions – a risk few city leaders are willing to take.

We need civilian police review boards with the authority to oversee recruitment, screening and training, conduct their own investigations when officers use lethal force and suspend or fire officers found in violation of clearly defined codes of conduct. (These suspensions or dismissals would be entirely separate from any legal action brought against the officers involved.) We need those kinds of boards but we won’t see them until a critical mass of white people in our cities, people who are part of the political power infrastructure, demand them to the point that the political cost to our city leaders of ignoring those demands exceeds the cost of bucking the police unions.

But a critical thing that need to happen to improve the current situation – and maybe the most important – is for members of the law enforcement community to take a stand.

Police officers face a difficult and sometimes dangerous job, putting themselves at risk every day to keep the rest of us safe. They have to develop an extraordinary level of mutual trust; if they can’t depend on their colleagues absolutely, they can’t do their job. The problem is that this camaraderie often involves not only dealing with situations on the street, but keeping mum when a fellow officer makes a serious mistake on the job or commits an act of gratuitous violence intentionally. Anyone who reports a colleague’s misbehavior becomes an instant pariah.

But at what point does the imperative to watch each others’ backs become more important than keeping the vow to serve and protect the public? When will more of the decent, well-intentioned public servants who make up the vast majority of the law enforcement community cross “the thin blue line” and speak out about those who use the badge as an excuse to commit murder?

At what point do the good cops hear about – or see a video of – the next Philando Castile or Alton Sterling and finally say enough?

Charles Coe is author of two books of poetry, “All Sins Forgiven: Poems for my Parents” and “Picnic on the Moon,” and the author of the novella “Spin Cycles.” He is the winner of a fellowship in poetry from the Massachusetts Cultural Council; was selected by the Associates of the Boston Public Library as a “Boston Literary Light for 2014”; and “Peach Pie,” a short film by Roberto Mighty based on his poem “Fortress,” was featured at this summer’s Los Angeles Short Film Festival. Coe is an artist fellow at the St. Botolph Club of Boston and co-chairman of the Boston Chapter of the National Writers Union, a labor union for freelance writers. Reach him at [email protected].