In response to our story today about car theft dropping significantly across the region and the country, readers have written in to suggest the decrease in car theft has caused carjackings to rise.

It is a decent theory, because newer cars are desirable but can’t be hotwired. “If you want to steal a nicer car, you pretty much have to carjack it,” said DC Police Chief Cathy L. Lanier

But the numbers show that carjackings also have come down significantly, including armed carjackings, which have dropped more than 50 percent in the District.

Carjacking is a violent crime, necessitating a criminal interacting with a victim, overpowering them and then stealing their car. Police detectives we interviewed said most car thieves aren’t interested in such a confrontation.

When carjackings happen, they are big news because they can be violent and terrifying.

Last week, a carjacker forced his way into a Lexus at a Baltimore gas station and took off with a woman and her toddler inside. After a 100 mph police chase, the woman dove out of the car with her son as they neared Bethesda. Both mother and child were fine.

While older cars are more likely to be stolen when nobody is looking, new “muscle cars” and luxury vehicles are sometimes targeted for carjackings.

Newer cars and their security systems, including anti-theft devices and computerized systems, make them very difficult to steal without the car’s specific key.

But carjackings have decreased in the District and Prince George’s County, the two local areas where the crime was once a major problem. The number of carjackings has fallen so much in the District that in May, Lanier pulled her officers from a squad that D.C. police had formed with the FBI’s Washington Field Office to investigate armed carjackings.

In 2008 there were 267 armed carjackings in the District. Between January and May of this year, the number had come down to 45, more than a 50 percent drop in the monthly average. Detectives on the squad arrested 162 people over two years for the crime.

In Prince George’s, carjacking fell from 768 attacks in 2005 to 207 in 2010, according to police data. That’s a decrease of 73 percent, outpacing the decline in auto theft.

Some of the carjacked vehicles end up being shipped to Africa — as our colleague Matt Zapotosky reported in a story about international car thieves in April — but most are stolen by criminals who stay local, said Supervisory Special Agent Timothy Doran, who oversees the Violent Crimes Task Force in the District.

“Here, it’s a thrill ride, you make your bones,” Doran said. “Sometimes they’d carjack one car just to go carjack another.”

He said the carjackers most often used guns and targeted “muscle cars,” which he described as a Dodge 300 or any nice car.

“If you’re going to steal a car, you might as well get one that goes fast,” Doran said.