(FOX2) – A man already out on bail for a separate crime involving possession of controlled substances was arrested again for carrying a concealed AR-15 style firearm.

According to the Oakland County Sheriff’s Office, the suspect now faces several more charges after its gun violence task force found he had 3D printed gun parts that turn firearms into automatic weapons.

The 13 devices used to convert Glocks into machine guns are now retired.

The sheriff said the devices, which appear to be harmless pieces of plastic, can turn the gun fully automatic.

“So instead of pulling the trigger once for each shot, you pull the trigger and it continues until it runs out of ammunition,” Sheriff Michael Bouchard said.

3D printed weapon modifiers

The person, who was not brought to court, was detained by the Armed Violence Taskforce over the weekend. After arresting him, the task force seized a 3D printer as well as modified devices.

“We believe that in addition to developing their own process, the individual also purchases them from other places,” Bouchard said.