Charlie T. Deane completed his last day as Prince William County police chief Sept. 1 after 42 years.

With Lt. Col. Barry Barnard named interim chief, the county is in the midst of a national search for Deane’s replacement.

Deane sat down with The Washington Post for a final interview before his last day, reflecting on his leadership style and detailing lessons for the job’s next inhabitant.

Here’s the edited interview.

Have you ever gotten influenced from outside forces — political or otherwise — about how to handle the department?

Nobody’s ever told me who to hire, who to fire. There’s been no political influence like that. Police chiefs can’t allow that.

Obviously the debate over illegal immigration comes to mind. [In 2007, Prince William supervisors passed a measure that many feared would lead to racial profiling. The measure was modified in 2008 — now, the county checks the immigration status of all those arrested.]

From the beginning I said, “I’ll do what you tell me to do” [to supervisors]. But I have a professional obligation to point out my concerns about the original policy. I think to this day what we’ve been doing is lawful. I had to point out the issues I saw . . . in terms of the more aggressive policy.

In the years since the illegal immigration law was passed, have you been happy with its implementation?

I think it is the right balance. If a community wants to do illegal immigration enforcement, I think focusing on people who commit crimes as a start is a no-brainer. I do not receive complaints about how we are handling it. I try to be very open, transparent. I think the department did a good job of taking on that responsibility.

Tell us a little about your leadership style over the years. Are you someone who constantly needs to be updated or generally tries to stay focused on the big picture?

It’s probably better for someone else to answer that question. Maybe they’ll answer that question now that I’m gone. But I think, I certainly know enough about crime at a crime scene to go under the tape.

I’ve found that the best way to know what you’re talking about when you’re dealing with a major issue is to talk to the front line. Someone . . . who was on the scene, whether you’re talking about a crime or a policy. I focus on minute details in some cases and keep a broad perspective as chief. I have to have the ability to be flexible, to focus on big issues and small issues.

I try to let the people who are in charge run the case. My job is to make sure they’re well trained and competent, and well equipped. I need to be looking over the horizon to make sure they’re getting the resources they need.

What are the biggest concerns you’re hearing from the community?

Always traffic. Traffic is, of course, a major responsibility. There’s concern about gangs. We have a specialized gang unit task force. Also, illegal drug activity. From time to time, we have a series of burglaries and street robberies that we need to keep an eye on, spotting trends and solving those cases.

You’ve seen our crime statistics. We’re really a very safe community, but we still have some horrible crimes.

Speaking of that, crime in Prince William has been trending downward for years. How is that possible in a growing, diverse community?

Bluntly, I don’t have an answer to that. I can talk about individual types of crimes and individual patterns we see.

We had a spike in robberies a few years ago, and we targeted these hot spots and arrested everyone who was doing illegal activity in those hot spots. We can be very effective when there are clear-cut patterns.

One of the worries I have today is everybody is talking about cleaning out the prisons. California is putting out people wholesale. We ought to be very careful about that, because we need to be methodical about who we’re letting out.

You’ve seen every level of law enforcement and interacted with all of them. What works well and what doesn’t work well?

In years past, my early career, we had considerable friction between us, our operations and federal agencies. Some federal agencies would conduct raids in the county without informing us. Of course, federal law gives them the authority to do what they want to do. But it’s not real bright.

But that has changed. I say today, after Sept. 11, and the sniper case . . . we have the best law enforcement resources in the country. That’s why we solve some of these cases.

Are there any downsides to how we use new and better technology?

One thing I always think about is the level of expectation is always raised when it comes to technology. If there was a video, I better find it. Or someone else is going to find it and either destroy it and save the person that committed the crime or it can wind up on YouTube tomorrow, and we look like dunces.

Juries also do expect more and more. They call that the “CSI syndrome.” But people believe what they see on TV, and they solve the case in 30 minutes. Some of it’s true. Who had ever heard of us being able to solve a 10-year-old case . . . through data banks? Think of the East Coast Rapist case. Who would have ever thought we would have been the ones who solved it? That DNA kind of lit up from here to New Haven, Conn., and we gathered all these different agencies together and brought them here.

In some organizations, you leave a memo when you leave. What do you want to make sure stays with the department?

To be sensitive to the community, the issues in the community and take care of the troops. It’s important for us to remain unbiased and independent of politics. I don’t know if that’s the right word. Police need to be right down the middle. Always conscious of the core values of the organization, treating people fairly and following the law. That’s not as simple sometimes as it seems.