KNOXVILLE, Tenn. (WATE) — A Knoxville man is facing federal weapons charges after an investigation into the sale of illegal parts from China that can convert semi-automatic firearms into machine guns.

An investigation by the Bureau of Alcohol, Tobacco, Firearms and Explosives into 23-year-old Derek Blalock of Knoxville began in January 2023 after they were informed by local law enforcement that he was suspected of selling Glock machinegun conversion devices, or MCDs.

These devices, commonly referred to as a “Glock Switch” or a “Glock Auto Sear,” can be attached to a Glock handgun to convert the semi-automatic pistol into a machine pistol capable of fully-automatic fire. Possession of the device is illegal under federal law without the required licensing.

An undercover ATF agent and a confidential informant executed multiple controlled purchases of MCDs and firearms equipped with MCDs from Blalock at his Knoxville home.

He told the informant the MCDs were ordered off “the black market” and came from China. Blalock also said he frequently sells firearms but that he needed to stop buying them in his name in case ATF ever came to question him.

Blalock told the informant on Feb. 1 that he would receive a shipment of MCDs by Feb. 6.

On Feb. 4, he was arrested by University of Tennessee Police after the car he was driving with his girlfriend and a one-year-old child crashed into a flowerbed near the Publix grocery store on University Commons Way. The officer observed a handgun with an MCD attached in the car and found a small amount of marijuana while searching Blalock.

He was charged with reckless driving, child neglect, possession of a prohibited weapon and simple possession of marijuana. While in custody, Blalock reportedly made a phone call to an unidentified male to retrieve a package containing MCDs at his mother’s home.

The next day, Blalock contacted the informant about the arrival of the shipment. An undercover agent purchased a modified Glock firearm and six AR-type MCDs from Blalock on Feb. 7.

A federal search warrant was then executed on his residence where agents recovered more MCDs, an AR-style pistol, 426 grams of suspected marijuana, 227 grams of methamphetamine pills, 50.5 grams of cocaine, 2.2 grams of suspected heroin as well as other drug paraphernalia.

Blalock told investigators he purchased the MCDs using cryptocurrency.

He faces federal charges of possession of a machinegun, possession of a firearm in furtherance of a drug trafficking crime, firearms trafficking, possession with intent to distribute over 50 grams of methamphetamine and possession with intent to distribute a mixture and substance containing a detectable amount of cocaine.