ST. LOUIS (AP) — In what’s been a violent year in St. Louis, a common theme has emerged: The gun used in any given crime was probably stolen.

The city is on pace for around 200 homicides in 2015, the most in 20 years. Meanwhile, reports of gun thefts are up nearly 70 percent, police chief Sam Dotson said. But it’s not homes, gun stores or pawn shops that thieves are targeting, Dotson said: It’s cars and trucks.

More than 170,000 Missouri residents hold concealed-carry permits and many bring guns when they venture to high-crime areas like St. Louis. Numerous city-dwellers, too, own firearms. But once they arrive at their destination, they often have to leave their guns behind.

“When they go to a baseball game or an event at the convention center … they can’t take their weapons in with them and they leave them in cars,” Dotson said. “Criminals know there are guns in cars and they break into cars.”

More guns are around overall. Both sales and applications for concealed-carry permits have spiked in the St. Louis region in the past year, after unrest that followed the death of 18-year-old Michael Brown led to safety concerns. Brown, who was black and unarmed, was fatally shot by a white officer last summer, leading to protests, some looting, fires and violence. When a grand jury declined to indict the officer in November, violence sparked again.

Experts say that, inevitably, with more guns come more gun thefts. Remy Cross, a professor at Webster University in suburban St. Louis, said those who steal guns often sell them to other criminals.

“It’s easy to move them,” he said. “If you have a gun and don’t intend to use it yourself, because of the loopholes in laws around gun shows and resale, it’s relatively easy to get these guns into criminals’ hands.”

Police say stolen and illegal guns are at the root of violence across the country.

In San Francisco, the gun used to kill Kathryn Steinle, who was fatally shot in July as she walked with her father along a scenic pier, was stolen. Chicago has already seized nearly 4,700 guns — nearly all of them stolen — this year. Police spokesman Anthony Guglielmi said that’s seven times more guns seized than New York City, and three times the number in Los Angeles.

“They’re the engine of violence in Chicago,” Guglielmi said. “These are guns that are on the streets used to fuel the violence in Chicago.”

In Jacksonville, Florida, gun thefts from cars are so common that police have launched a social media campaign to persuade people to keep their weapons at home.

“It’s a big issue,” Jacksonville Sheriff’s Office spokeswoman Melissa Bujeda said. “Criminals are just going car-hopping, looking for unlocked doors and people who are leaving their guns in their cars.”

There is no updated national data on gun thefts, but a U.S. Department of Justice Bureau of Justice Statistics report found that 1.4 million firearms were stolen across the country from 2005 through 2010. It also found that the vast majority — at least 80 percent — were never recovered.

Suspects who authorities say were wielding stolen guns were shot by St. Louis-area police in two recent high-profile cases, worsening racial tensions that have simmered since Brown’s death. Both of the 18-year-olds shot this month by police also were black.

During a protest in Ferguson on Aug. 9 marking the one-year anniversary of Brown’s death, Tyrone Harris Jr. shot at undercover officers using a semi-automatic 9 mm gun that was stolen last year from Cape Girardeau, Missouri, police said. Officers fired back, striking Harris several times. He was critically wounded.

Last week in north St. Louis, Mansur Ball-Bey ran out of a home during a raid and was fatally shot after pointing a gun at officers, Dotson said, though the attorney for Ball-Bey’s family claims that he was unarmed. Investigations by an internal police unit and the city’s Circuit Attorney’s office continue. Dotson said Ball-Bey’s handgun had been stolen in Rolla, Missouri, about 100 miles southwest of St. Louis.

Since Ferguson, concealed-carry permit applications in St. Louis County have more than doubled, police said. The county had 7,881 applications in the past 12 months, compared to 3,194 for the 12 months prior to Brown’s death, a police spokesman said. St. Louis city police said permit figures were not available.

“I think the message is that lawful people who want to have a gun, be smart about it,” Dotson said. “Don’t leave it unsecured in cars.”

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