While the Washington region has seen car thefts fall dramatically over the past seven years — dropping more than 50 percent in the District and Prince George’s County, for example — the decline is part of a nationwide trend. As we reported in our story on Sunday, the change is a result of a combination of new anti-theft technology and aggressive police efforts.

The West Coast has faced the toughest test in this regard in recent years. Eight of the 10 worst metropolitan areas for car theft in 2010 were in California, according to statistics from the National Insurance Crime Bureau. The other two were in Washington state. (The Washington, D.C., area ranked 78th.)

In Arizona, which at one point had among the nation’s worst auto-theft rates, the crime has dropped precipitously as the state aimed to hit the problem head-on. It provides an interesting example of how such changes take place in a short period of time.

Car thefts in the United States have been steadily dropping since 2003, the last year that saw any kind of overall increase. That year, there were 1.26 million auto thefts, according to data in the FBI’s annual Uniform Crime Report. Preliminary national numbers for 2010 show that those thefts fell to fewer than 738,000, a drop of 42 percent.

From 2008 to 2009, Arizona’s car thefts declined by one-third, the largest single drop in the country that year. It was a welcome change that authorities said was a long time coming.

Sgt. J.D. Hough of the Arizona Department of Public Safety said his state’s success came from legislation that targeted auto thieves with stiffer penalties and cracked down on fraud; the use of license-plate readers and bait cars; and the sharing of information about the problem among state and local agencies and the insurance and auto industries.

“We’re real hard on seeing that people get prison time,” said Hough, who supervises an Arizona Vehicle Theft Task Force squad in the Phoenix area. “Professional car thieves and chop shops have dropped significantly in the area because we’ve dismantled a number of organizations. It’s all about deterrence. . . . We’ve been able to put a dent in it. It seems like we keep going down, and it’s awesome.”

Hough, a past present of the western regional chapter of the International Association of Auto Theft Investigators, said technology has been a large part of the solution, too. License-plate readers allow police to passively scan thousands of plates in a fraction of the time that it would take officers to manually run them. Cars that have immobilizing computers and keys with computer chips stop many thieves.

“That’s why you see the older models as the most stolen vehicles,” Hough said. “They know which ones they can hit. Some of the gangs out there know that this car, all you have to do is this and this and away you go, and that knowledge gets passed around.”

Hough said the success in Arizona has led to another concern: dwindling resources for fighting auto theft. His task force has gone from six squads to three because agencies have been pulling their people out for reassignment.

“I’d hate to see everyone think that auto theft is way down and then it makes a comeback,” Hough said. “Right now, it frees up officers to take care of the violent crimes, so it’s a win-win.”

Law enforcement officials and auto industry experts say car theft will never disappear, not as long as there are people who want to make a buck off of someone else’s car and have the wherewithal to carry out the crime.

But officials are buoyed by the progress that has been made in a relatively short time, and they believe that the trend will continue, especially as older cars leave the roadways and are replaced by newer, more impenetrable models.

“We’re doing pretty well,” D.C. Police Chief Cathy L. Lanier said. “We want to keep going in that direction.”