UPDATE: On the morning of April 5, 2022, the Sacramento Police Department said in a news release that it had determined a handgun recovered at the scene of the mass shooting had "been converted to a weapon capable of automatic gunfire."

California law enforcement officials suspect a handgun converted to fire like a machine gun was among the weapons used in the mass shooting that left six dead and 12 wounded in Sacramento on April 3. 

The shooting began after a fight broke out around 2:00 a.m. in a popular nightlife area just blocks away from the state Capitol. Video from the scene shows chaos and a crowd scrambling after gunshots ring out, including a burst of the sort of rapid fire that typically comes from a machine gun. 

Law enforcement sources say witness reports, physical evidence, and videos of the events that night have led them to believe that at least one of the guns used was a fully automatic weapon, most likely one that was equipped with an illegal conversion device. 

“Both the duration of the gunfire and the number of casings recovered are consistent with full-auto fire,” said a law enforcement official with knowledge of the investigation.

A second law enforcement source who was near the scene described hearing what sounded like full-auto gunfire, which echoed off the tall buildings in downtown Sacramento. It’s believed that “multiple shooters with multiple guns” were exchanging fire. Photos from the aftermath of the shootout showed the pavement littered with shell casings that appeared to be of handgun caliber.

Last month, The Trace and VICE News documented the rise of automatic conversion devices, which quickly and easily modify semiautomatic weapons to fire more than 1,200 rounds per minute, and sidestep the federal government’s strict licensing requirements for automatic weapons. Our reporting identified hundreds of cases where criminals and extremists sought out and used conversion devices to carry out robberies, assaults, and murders. According to the Bureau of Alcohol, Tobacco, Firearms and Explosives, recoveries of illegally modified machine guns increased from 300 in 2020 to 1,500 last year. 

Commonly referred to as “switches” or “chips” on the streets, automatic conversion devices are available for illegal online purchase for as little as $20, and can even be fashioned at home using a 3D-printer. Among the most popular type of conversion device is the auto sear, which is commonly used with Glock handguns. 

The Sacramento Police Department confirmed that at least one stolen firearm was recovered at the scene, and another retrieved during a search warrant. The police also said more than 100 shell casings were recovered at the scene.

Asked whether a Glock modified with an auto sear was used in the shooting, a spokesperson for the Sacramento Police Department said that “determining the functionality of the weapons involved in the shooting will remain a focus during the investigation.” 

Sacramento police said they had arrested a 26 year-old man as a suspect in the shooting, but continued to search for additional suspects. 

This would not be the first time an automatically converted weapon was linked to a mass shooting. In 2019, members of the Mongolian Boys Society, a criminal street gang, used an automatically converted Glock to kill four and wound six more at a family gathering in Fresno, California.