Thefts from gun dealers in Colorado hit a 10-year high last year, raising concerns about a flood of deadly weapons being readily available for perpetrators of violent crimes.

The local upswing mirrors an increase in thefts from gun dealers nationally. Law enforcement officials are working with licensed dealers in widespread, cooperative efforts aimed a reversing the potentially deadly trend.

Last year 273 guns were stolen from dealers in Colorado, up from 56 in 2014.

“We are very concerned about the rise in gun thefts. These guns will not be used for hunting or sport; they are destined for future crimes and are a threat to public and officer safety,” said Debora Livingston, a federal agent with the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives.

Nationally, in 2016, the number of guns stolen from federally licensed dealers climbed to 7,858 — the highest number on record. In 2016, 7,488 guns were stolen nationwide from federally licensed dealers during burglaries, up from 4,721 in 2015.

Thefts from gun dealers typically happen in the dark of night, when stores are closed. Smash-and-grab thieves ram storefronts with stolen vehicles and dash on foot into the business through smashed windows, walls and doors. The thieves ransack the store, quickly grabbing as many guns as possible before running out and fleeing in a secondary, waiting vehicle.

Federal, state and local law enforcement are carrying out a multipronged approach to catch the criminals and recover weapons. They are contacting the dealers who were victimized as well as surrounding dealers to pass along information about theft prevention and to heighten dealer awareness.

Dealers can sign up for automated telephone calls that warn of robberies and attempted robberies nearby. Law enforcement also offers seminars on security and preventive measures.

“We are making suggestions and recommendations on security measures taken by gun dealers,” Livingston said.

A secure storefront with metal gating, deadbolted steel doors and wired glass that triggers an alarm are recommended. But these measures can give a false sense of security. Law enforcement agencies are pitching secondary layers of security inside the stores that include securing all weapons, interior motion detectors, glass break detection, audible security alarms and maintenance to ensure all security systems are working properly.

“Additional measures slows (thieves) down,” Livingston said. “They’re not spending a long time in the store. They’ve got to get out quickly.”

If criminals can’t scoop weapons quickly, they’ll race out empty-handed knowing their entry has triggered an alarm and police are on the way.

Most thieves are local, and most of the stolen weapons stay in the state. The stolen weapons, predominantly handguns, often are sold on the street to other felons or are exchanged for drugs. These guns sell on the street for $100 to $400 for handguns, $300 to $600 for a shotgun or rifle.

“The initial theft is dangerous in and of itself,” Livingston said. “These guns then go on to be in the hands of other criminals, people who can’t purchase them legally. The guns are going to be used in crimes. They aren’t just a danger to law enforcement; they’re a danger to the public.”

In the past year, ATF and police have arrested 15 suspects and recovered 55 firearms stolen from dealers in Colorado. Some weapons have been recovered during investigations of violent crimes.

“These are weapons used to harm and kill other people,” said Bob Troyer, acting U.S. attorney for Colorado.

In February, Eric Michael Perez, 20, of Denver was sentenced to just less than six years in federal prison for his part in a June 21, 2016, theft of 35 guns from the Colorado Gun Broker in Jefferson County.

Prosecutors in recent years have made strides convicting those involved in straw purchases of firearms. Such crimes can include sellers of firearms lying about the identity of the purchaser or a surrogate buyer purchasing a weapon for third party, possibly a felon. Success in such convictions likely has reduced the number of guns on the street, and that, in turn, likely has fueled the uptick in late-night smash-and-grabs at storefronts.

“It’s a record-breaking year. We don’t want to hide from that or minimize it,” Troyer said. “It’s a serious risk, and we are throwing everything we have at it.”