SACRAMENTO, Calif. (KTXL) — The weapon recovered at the scene of the shooting in downtown Sacramento was no ordinary handgun. 

Sacramento police confirmed a kind of machine gun was recovered from the scene. 

“The stolen handgun was converted to be a fully-automatic handgun, capable of being fired fully automatic,” said Sgt. Zach Eaton. 

Don Ratkowski is a Marine corps veteran and owner of Protection Plus Tactics in Loomis. 

“Criminal elements making these things more readily accessible to criminals. That’s what’s happening,” Ratkowski said.

Ratkowski said he works with law enforcement and other agencies. 

“We work with firefighters, and we work with civilians, teaching them how to protect themselves,” Ratkowski said. 

He demonstrated to FOX40 how a semi-automatic handgun, which can be legally purchased, shoots only once for every pull of the trigger. That’s because of a regulating device inside the gun called a sear. 

“In a semi-automatic, as I let the trigger out, you’re going to hear a click. That’s the sear reengaging. That’s what allows it to now be fired again. So, now I can engage the trigger and pull it, and you’ll hear a click again. That is what the sear does,” Ratkowski said. 

But criminals are making and selling devices called auto sears, which are illegal in California. They are small components, and when they are installed into semi-automatic handguns, they override the sear, making the gun fully automatic. 

“With a fully automatic weapon, you pull the trigger and hold it, it’s going to keep firing rounds until you let go of the trigger,” Ratkowski said.

He explained that those guns are difficult to fire with accuracy. 

“When you turn a Glock or a pistol from a semi-automatic into a fully-automatic weapon, you’re talking about a very violent recoil. So, you have to manage and control that weapon,” Ratkowski said. 

An investigative report by Vice News and a nonprofit news outlet called The Trace revealed a growing problem. Looking at federal prosecution records, they found auto-sear devices were recovered in 12 federal cases in 2017. 

That number rose to 203 last year. A retired firearms expert with the Bureau of Alcohol, Tobacco, Firearms and Explosives who spoke to FOX40 by telephone said the devices present a serious challenge for law enforcement. 

“The quantity of stuff that comes into a port, the billions of pounds that come in on a daily basis, stuff just gets missed. Or it gets put in the mail, and you call it electronic components or mechanical components. And it gets X-rayed, and unless you really know what you’re looking for, you’re not going to find it,” said Rick Vasquez, retired firearms expert. 

From Ratkowski’s perspective, based on the evidence revealed by police, the situation in Sacramento is the latest frustrating example of criminals gaining an upper hand over lawful gun owners. 

“We had the law in effect in California, you are not allowed to put an auto sear in your weapon. You are not allowed to own a weapon as a felon. Yet, that individual that committed those acts was a felon, was not allowed to own a gun,” Ratkowski said.

“It was a stolen firearm. He converted the weapon illegally. Everything the man did was illegal. So adding more laws would have just been more laws he broke,” he continued.

The retired ATF agent FOX40 spoke with said the auto-sear devices are largely coming into the U.S. from other countries, and to many inspectors, they might look like ordinary mechanical components.