Computer programs can recognize faces, watch for signs of trouble and attempt to locate gunshots.

In some law enforcement agencies, officers even wear small video cameras. The recordings may help settle any questions about the behavior of officers or the people they deal with.

The use of video cameras can raise privacy concerns, but Professor Burke points out that these days almost everyone has one.

TOD BURKE: "Let's face it, many people have video cameras themselves, many attached to their phones. And that is also aiding in law enforcement efforts -- what I call video vigilantes. Everything is being videotaped, and much of it is going onto social networks such as YouTube and Facebook."

But officers worry that some people are just looking for a chance to try to make the police look bad while doing a dangerous job.

Officials are concerned about an increase in the killing of law enforcement officers in the United States, even as crime rates have dropped.

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BOB DOUGHTY: Our program was written and produced by Brianna Blake. I’m Bob Doughty.

FAITH LAPIDUS:

And I’m Faith Lapidus. You can find transcripts and MP3s of our programs at voaspecialenglish.com. You can also find a link to that "Broken Windows" article by George Kelling and James Q. Wilson that appeared in the Atlantic magazine. Join us again next week for THIS IS AMERICA in VOA Special English.