August 9 marked the one-year anniversary of the death of Michael Brown, the unarmed black teenager who was shot and killed by Darren Wilson, a white police officer, in Ferguson, Missouri. A proliferation of similar incidents has made headlines in the months since. There was Tamir Rice, a 12-year-old boy gunned down in Cleveland, Ohio, after brandishing a fake gun at a recreation center. There was Walter Scott, a 50-year-old man shot to death in North Charleston, South Carolina. Most recently, there was Christian Taylor, the 19-year-old college student killed in Arlington, Texas. Like Brown, all of these victims were unarmed and black, and all of the shooters were white police officers.

The guidelines that govern when and how a cop decides to fire a gun are opaque at best. To gain a better a understanding of the rules regarding the use of deadly force, The Trace spoke with Tom Nolan, a former lieutenant and 27-year veteran of the Boston Police Department. After leaving law enforcement, Nolan worked as a senior policy analyst in the Office of Civil Rights and Civil Liberties at the Department of Homeland Security. Now he runs the graduate criminology program at Merrimack College in North Andover, Massachusetts, where he studies police subcultures, practices, and procedures.

When Darren Wilson first encountered Michael Brown, he identified him as a suspect who’d recently stolen cigarillos from a convenience store. Then he pulled in front of Brown and barricaded the roadway, and chose to initiate contact from inside his vehicle, which led to a scuffle over his firearm. In a recent interview, David Simon, creator of The Wire, was very critical of this tactic, calling it “the worst police work I’ve ever seen.” What’s your take?

Tactically and strategically, Darren Wilson did nothing right. His decision to maneuver his police cruiser in whatever way he did actually ended up facilitating what transpired. Ordinarily, you get on the radio and say you see the guy from the convenience store [Michael Brown], but you wait for backup. He allowed himself to be boxed in. He had three implements at his disposal: a baton, pepper spray, and a gun. But because it was either inconvenient for him or inaccessible to him — because he was in his car — the only thing accessible was his firearm, and that’s what he chose to use. You don’t approach someone like that with your police cruiser.

What should he have done?

You pull up behind the person and keep them in your eyesight while you wait for backup. Then you make your confrontation, and you do it on foot.

Within the law enforcement community, what’s the reaction to intense scrutiny now being given to officer-involved shootings?

The police very much see themselves as the victims of this whole thing. They’ve created this institutional persona of being heroic, seeing themselves as good guys. Now this narrative they’ve created is being eroded. It’s been taken away from them by activists and people on social media. I don’t think we’re seeing a sharp increase in the number of individuals being killed by police, but a marked increase in exposure. Agencies are hiring too many unqualified people — like Darren Wilson. The vast majority of cops are diligent about their duties and they’re respectful and qualified to be where they are, but there are too many of them that don’t belong.

What makes a person unqualified to be a police officer?

Most places, you take a pencil and paper test, which doesn’t measure anything. There’s a physical exam, and usually, there will be a psychological exam. There’s also a background check, and as long as there are no felony convictions, you’re eligible for hire. But there’s no attempt made to see how suitable you are to be hired. Cities like Ferguson don’t have resources to do a rigorous evaluation. They’re going to get who they get — the less desirable candidates. You get the Darren Wilsons of the world.

What does a rigorous evaluation look like?

Rigorous psych evaluations would entail a candidate being interviewed by more than one mental health professional, and standardized psychological tests would be administered. The health professional would make assessments about temperament, and if that person is thorough enough, they can figure out if someone has a hair-trigger temper or thinks conflict resolution should be physical in nature. They can also figure out if someone has racial animus toward certain groups. These are the people you don’t want to hire as police officers, who you don’t give a badge and gun.

Because if you do, it leads to bad decisions.

Right. The policies, in and of themselves, are fairly restrictive across the board. You must be confronted with probable cause that someone has committed a violent felony crime, during which he used or threatened to use a weapon and threatened to harm civilians. Or he has a weapon when he’s confronting you, and a delay would result in serious injury or death.

Has the rise of concealed carry, and in some instances, open carry, changed the way officers police?

States that have the highest ownership rates of firearms also have the highest rates of officers killed in the line of duty. In states where there are fairly nonrestrictive concealed-carry laws, police officers have the expectation that people they come into contact with will be armed, and when they go into homes, they have to assume there’s a gun in the home. That creates a keen awareness. And that’s different than the policing that I undertook in Massachusetts, which has strict gun laws — it was very unusual to encounter someone carrying a concealed weapon there. In states with nonrestrictive gun laws, when you go into homes, you have to assume there’s a gun in the home.

Does that keen awareness make cops more likely to pull the trigger?

Certainly, officers coming into contact with firearms on a regular basis would lead to heightened anxiety. So yes, it may lead to a situation in which officers are more likely to unholster a weapon.

Do you think the majority of police shootings are justified?

I would say the majority are. These instances that we’re seeing are outliers, but it does pull back the curtain on a dirty little secret that police have kept for decades. There are instances — we call it a “bad shoot” — where officers use deadly force, and in police subculture it’s known to be questionable. There’s an expectation among officers that they’re going to be exonerated, and the shooting will be justified. We did this for decades: firing at moving vehicles, for example, and then saying the guy is trying to run me down. That was the default. Common sense would say it took you longer to get your gun than to move out of way.

What needs to happen to limit the kind of shootings we’ve seen in Ferguson and elsewhere?

A lot has to do with a department’s culture. For example, in the mid-aughts, Richmond, California, was the murder capital of the United States. Being that it had such a high homicide rate, it also had a high officer shooting rate. It was like the Wild West there, and deadly force was frequently used and endorsed by the institutional subculture.

Then they brought in this guy from the outside, and in his first five years there, he had no officer-involved shootings. That was remarkable. Part of the reason was that he went in and set the tone from the top — that deadly force was going to be an extremely rare exception. That message needs to come from the top. And the follow-up needs to be this: If you engage in a deadly force incident, there will be a meticulous investigation, and if it violates our rules and procedures, you’re going to get fired.

One thing that resonates with cops is discipline. Ferguson, for example, hasn’t reported an officer-involved shooting to the FBI since 1973. The thought is: We’re in hostile territory, and we do what we have to do, and if that includes gunning someone down, we take care of business. But if the message goes out that we no longer conduct business in that fashion — if one time someone violates procedures and policies and you discipline them — other cops will get the message.

[Photo: Flickr user @mjb]