GRAND RAPIDS, Mich. (WOOD) — An illegal device that converts semi-automatic pistols into machine guns has wrought devastation on streets across the country.

Now, a West Michigan man is accused of trying to sell the conversion mechanisms, known as “Glock switches.”

“Nationwide, it’s huge,” said retired Bureau of Alcohol, Tobacco Firearms and Explosives agent Brian Luettke, referring to the trafficking of Glock switches.

“They’re everywhere. … People (are) getting them mail order, illegally, overseas, shipped to their house … or they’re 3D printing them,” explained Luettke, who now runs his own business, Firearms Training & Interstate Nexus Consulting. “A Glock switch is approximately an inch (long), and it sticks off the rear of the slide. … Somebody with a Glock switch can put it on their Glock in, easily, less than a minute.”

While federal firearms licensees can obtain the devices legally with specialized permitting, Leuttke said there’s no lawful reason for civilians to possess Glock switches.

“If they’re used in the wrong environment, it is going to be catastrophic,” said Luettke. “If gang members have them and there’s a rival gang shooting, and they’re shooting at each other, there will be innocent people hit as well.”

That’s exactly what happened in downtown Sacramento in April. Six people were killed amid a barrage of bullets exchanged by competing gangs.

Sacramento police said at least one of the shooters had used a “switch” device to convert his semi-automatic pistol into a machine gun.

In September, a Houston police officer was killed while serving a warrant when the fugitive sprayed bullets from a handgun modified to shoot like a machine gun.

“They can empty the magazine, all rounds, with one pull of the trigger,” explained Luettke. “That’s 33 rounds in less than two seconds. If you’re shooting 33 rounds in less than two seconds, there’s no telling where those rounds are going to go. (The weapon is) hard to control. There’s a spraying effect. … There will be innocent people hit as well.”

On July 1, ATF agents in West Michigan seized several Glock switch devices from a home on Blackmer Road in Ravenna.

According to federal court documents, a confidential informant told agents the man who lived there, Zebulon Timothy Nester, had been trying to sell the converters along with other firearms.

Nester, 26, had been released from prison in January after serving time connected to a shooting at a Kentwood house party in August 2013.

When agents searched Nester’s home in July, they said they found handguns, long guns, several Glock switches and a 3D printer agents believe Nester was using to create the conversion devices.

Nester is currently housed at the Newaygo County Jail, charged federally with being a felon in possession of a firearm.

“Law-abiding citizens are not buying (Glock switches),” said retired agent Luettke.”Lawful gun owners are not using (conversion units). It’s usually people involved in drug trafficking, gangs.”

Possessing a Glock switch, even if it’s not connected to a firearm, carries up to ten years in prison.

Under federal law, the switches themselves are considered machine guns, which were outlawed for civilian use in the U.S. in 1986.

Luettke said criminals began importing the conversion mechanisms from China at least a decade ago.

“They’re not traceable. They don’t come with a serial number,” he said.

The Newaygo County Sheriff’s Department told News 8 Nester is also facing local charges for allegedly breaking into a home south of Hardy Dam in early June.