Every time a new police-involved shooting churns up another round of protests, police officers themselves tend to either defend the accused cop or to remain quietly on the sidelines. But in the case of Robert Bates — the “reservist” sheriff’s deputy in Tulsa, Okla. who shot and killed Eric Harris, an unarmed black man, after mistaking his own gun for a TASER — police officers around the country were sure to have a point of view.

That’s because reserve and part-time cops enjoy a decidedly uneven reputation among experienced full-timers, one of whom The Marshall Project interviewed this week.

Below, a sampling from our conversation with Lieutenant John Walker, a veteran detective with the Philadelphia Police Department, who says that he and other long-time police officers share a low opinion of reservists. To Walker, the use of these part-time officers is indicative of a larger problem — a short-term, low-engagement brand of policing that causes some cops to rely too heavily on violence.

Have you been following this case?

Yes, I have. I know that the reservist you’re talking about, he had a lifelong dream of being a police officer, and that he had a lot of money to go and make it a reality.

That means that policing was a hobby for him. People with that part-time attitude get into this to have power, feed their ego. That bothers real full-time police officers, definitely.

Do you feel that way about all reservist and part-time cops?

Yes I do, I think the whole concept is not good for policing. If we’re going to avoid situations like this one and what we saw in Ferguson, what we need are officers who have long-term experience in de-escalating situations.

Not these guys who are in uniform once a month — or even, you know, if there are full-time officers who treat the job as a gig, a trip. Those are the guys who end up using force because they’re not actually trying to learn, learn, learn on a daily, weekly, monthly basis about real people and about encounters.

Explain what you mean by that.

I’m saying I think this question about reservists really gets into the whole thing about Ferguson, even though I don’t think there were any reservists involved in Ferguson, or the other [recent police-involved shootings].

Part of the hysteria is what the people say we aren’t doing. You know, that we aren’t trying to spend our time engaging with and getting to know the community. We’re not interacting with people on a human basis, as neighbors. Or we have no interpersonal skills, aren’t trying to help people and get them back on track. All of that.

People are pissed because they say that instead of doing any of that, the police are treating every situation as a use-of-force situation.

What does all of that have to do with reservists?

Well, using part-time reservists is an example of under-emphasizing these long-term, human skills that we as police officers have to develop over days and weeks and months and years of day-to-day engagement with real people.

These part-timers by definition aren’t spending their time with the community. They don’t have daily interpersonal interactions, which develops their mental reflexes for identifying what’s a use-of-force situation and what’s not.

And if you’re not experienced with that stuff, your first instinct is going to be your TASER. Inexperience is what causes over-reaction.

Explain how experienced, full-time police officers develop the skills you’re talking about.

The things we see out there, for those of us who are doing it every day of every week, are truly incredible. The goal is always to de-escalate, right? But then we’re also in the worst-of-the-worst situations, with lives on the line.

And then within that, there are always differences between encounters. Every single one is different. Sometimes it’s out on the highway, other times it’s in a high-rise. Often there is someone with mental illness involved, and the key is to identify that.

So when we’re doing this every day of every week, we learn to assess trends, learn our environment. I make adjustments every day.

What do you learn specifically about the use of force?

I think what we learn is that 90 percent of the time, our mere presence alone will de-escalate a situation. Then maybe eight or nine percent of the time, we can de-escalate the situation just by talking, by our interpersonal skills that we’ve picked up by doing this on a daily basis for so long.

That leaves just one percent of the time when we should ever have to use a TASER or a tool like that, and even less of the time when we should need to discharge our firearm.

Couldn’t reservists learn that through basic training?

No. It’s about muscle memory. Hours are important. You can’t do it if it’s not daily.

If you don’t have this everyday experience, you might not know that 98 to 99 percent of situations that seem threatening can actually be de-escalated by talking. And so you overreact.

Are there other benefits to maintaining a long-term relationship with the community, rather than employing part-timers and otherwise engaging with citizens on a part-time, in-and-out basis?

Yes, and I think there was an example from here in our department. I really think Philadelphia could have been Ferguson before there was Ferguson.

Opening Statement Sign up for our daily newsletter covering the best in criminal justice news.

Back in April 2014, I think it was, there was an event where some of our officers in plainclothes shot a young black kid who was wearing a hoodie. And we all knew pretty quickly that this was a bad, bad mistake to shoot him.

So what we did was we didn’t stand aside, backs against the wall, and let the conversation with the community develop without us. Instead we tried to engage the conversation and speak up for ourselves as it progressed, and be honest about what we had done wrong.

It’s that relationship with the community — of trust — that you develop over a very long time and that prevents the hysteria and uproar.

Are you bothered on a personal level by the concept of reservist police officers?

Yes, because good officers need to be committed, 100 percent, to the job — when you’re committed to something, you take it seriously. And policing is nothing if not serious. We can take away people’s lives. We can take away their freedom, their liberty, which is always a tragedy even though it sometimes has to happen.

Being focused on these responsibilities only a day a week or a week a month is almost by definition not having that commitment.

Why do you think some departments do rely on these types of officers?

I mean, it’s a financial thing. Guys like [Robert Bates] bring money in for the police — a lot of money. And for these places that are cash-strapped, it’s appealing; it means they can get their toys.

But to me that crosses an ethical line. We bring you on as a millionaire, use you as a cash cow, essentially, and in return you expect certain things. You get a deal where fair and honest supervisors are targeted for saying that you aren’t ready for real duty.

I think that these governments that have an actual need to spend more money on policing, they need to find it in the real budget rather than trying to pretend there is no cost to this stuff by getting the money in these risky ways.

Do you think it’s ever a good idea to employ these reservists?

Sure, definitely for help in the office — clerical work, things like that.

Also they can be very useful in certain situations where you don’t want officers in uniform, like at this picnic of black fraternities that we had a little awhile ago. We had volunteers who were working with us part-time and didn’t have the gun and uniform — we had them go out there and be seen when we didn’t necessarily want a heavy police presence.

But if you’re a part-timer, you should never wear the uniform. The public has to know, really know on a basic level, who they’re dealing with.

This interview has been edited for length and clarity.