Lathrop Police may have thwarted disaster over the weekend after arresting a drunk driver with a passenger that was carrying a concealed, un-serialized handgun.

According to the agency, graveyard officers on Friday night stopped a vehicle for speeding and equipment violations and were able to determine that the driver had been drinking alcohol.

 Officers were also able to determine that the passenger inside of the vehicle was on federal probation, and when searched was in possession of a loaded, semiautomatic pistol that did not have any serial numbers on it.

The passenger was also in possession of a loaded, 31-round magazine.

The driver was arrested for driving under the influence of alcohol with a blood alcohol level above .08 percent while the passenger was taken into custody on charges of being a felon in possession of a handgun, being a felon in possession of ammunition, and carrying a loaded, unregistered firearm.

In recent years, guns like the one recovered by Lathrop Police have become much more prevalent thanks to the internet. In the release about the arrest the agency identified as the type of gun a “polymer 80 lower” handgun – which means it was purchased as a nearly-complete gun without the serial number. The 80 percent complete lower receiver is then supposed to be “finished” by a reputable gunsmith that will machine the remainder and then submit it for serialization.

When that process is bypassed, and the purchaser either finishes the work on their own or takes it somebody with the tools and knowledge to do so, the gun is fully functional and unable to be traced – making it incredibly hard for law enforcement to track its use in crime.

To contact Bulletin reporter Jason Campbell email jcampbell@mantecabulletin.com or call 209.249.3544.