In the most violent summer in Minneapolis in more than a decade, police have discovered a clue that could be key to closing more than a dozen unsolved cases: a single Glock .45 caliber handgun.

Using forensic technology, agents from the federal Bureau of Alcohol, Tobacco, Firearms and Explosives have linked the same gun to 14 recent crime scenes in Minneapolis, including a murder, several gang shootouts and a drive-by shooting on Interstate 94.

Matching the gun doesn't solve these other cases, but it provides a major break in the investigations, said Jeff Reed, assistant special agent in charge of the ATF's St. Paul field division. Investigators are now working backward to discover the gun's previous owners, which could lead to charges.

The system used to trace the gun to the other shootings is called National Integrated Ballistic Information Network, or NIBIN for short. Crime lab technicians decode the tiny, unique markings every gun leaves on a shell casing, similar to a fingerprint, and match them to shells found in other crime scenes.

In Minneapolis, NIBIN is becoming a critical tool in law enforcement's strategy to slow the surge of gun violence. So far in 2020, the ATF has confirmed 759 matches — called "hits" — through NIBIN, 70% more than last year, according to Minneapolis police data.

The 14 hits off the Glock .45, which Minneapolis police confiscated in the back of a restaurant earlier this year, are the most Twin Cities law enforcement has ever found from a single gun, Reed said.

The Glock's migration from shooter to shooter is the latest evidence of a pattern that's become more clear to law enforcement through the use of NIBIN: On the streets, guns travel faster and farther than previously understood.

The case is also a reminder of how much violence a single firearm can leave in its wake, said Minnesota U.S. Attorney Erica MacDonald.

"Cliques and gangs and groups tend to pass the firearms around," MacDonald said. "So by getting one gun off the streets, we're able to prevent dozens of crimes from occurring."

The last person to possess the Glock .45, according to police, was a man named Jarvae Somerville.

In July, Minneapolis police were investigating 28-year-old Somerville in connection with a shooting on the North Side. Officers followed him to A & J Fish and Chicken on East Lake Street. When Somerville saw the officers, he darted through the back of the restaurant, then pushed into a small private bathroom off the kitchen, according to a sworn affidavit from an ATF agent underlying the complaint.

Minneapolis police officer Andrew Schroeder chased after him, and the two tangled in the bathroom, ripping a sink out of the wall and tearing the seat off a toilet as Schroeder eventually wrestled him to the ground, according to the charges.

The Glock .45 fell out of Somerville's waistband and landed on the bathroom tile, the charges say.

Somerville, who was previously convicted of three assaults, was charged in federal court with being a felon in illegal possession of a firearm. His attorney, Ryan Pacyga, emphasized that Somerville is charged with possessing the gun only at the time of his arrest — not in any of the other shootings — and he plans to dispute some of the evidence at an upcoming court hearing.

After Somerville's arrest, the gun went to a crime lab for NIBIN testing. To examine the gun's signature, lab technicians fire it into a large metal tank. Water inside slows the bullet and a net catches the shell casing intact. Then they put the shell into the NIBIN system, which takes 3-D images of the shell and sends them to an ATF lab in Alabama. Analysts there study micro-impressions left by the gun's breech block and firing pin, and compare them to markings in shell casings taken from other crime scenes. A match is not enough evidence to file charges, but it creates new leads for police to follow through traditional investigative methods.

On July 10, two days after Minneapolis police took the gun off Somerville, a NIBIN report was placed on Assistant U.S. Attorney Amber Brennan's desk.

It showed 14 hits.

Solving these 14 crimes would provide a welcome boon in case closure rates for law enforcement in the Twin Cities.

In November, the toll of people maimed or killed by gunshots this year surpassed 500 in Minneapolis, more than double the 2019 figure and by far the highest in 15 years. Guns were used in almost all the city's 79 homicides this year, the highest homicide count since the violent mid-1990s era when the city was known as "Murderapolis."

"We know there's a very limited number of people who account for the vast majority of gun violence that occurs on our streets," MacDonald said.

This summer, the U.S. Attorney's Office in Minnesota started a task force with federal agents and local police designed to take some of those shooters off the streets. In 60 days, the task force confiscated 156 guns, leading to 22 federal charges, MacDonald said.

One of them was Somerville.

Law enforcement would not talk in specifics about the previous shootings to which they've linked the Glock, citing active investigations. But the U.S. Attorney's Office provided a summary of the 14 incidents. Most occurred in north Minneapolis; eight took place between April and July of 2020.

According to those records:

The gun first surfaced on the radar of law enforcement in October 2016. Minneapolis police responded to a call from ShotSpotter. Police arrived at the alley in north Minneapolis to find no victim or shooter, just a few shell casings, which they collected for NIBIN testing.

In May 2019, police pulled over a vehicle in north Minneapolis to find the driver had been shot multiple times. The officers found casings from the Glock on the intersection where the shooting occurred.

In April 2020, Minneapolis police responded to a shooting in a house in the Near North neighborhood. The victim was pronounced dead there. The details provided by prosecutors match the killing of 27-year-old Kevin Beasley, the grandson of longtime Minneapolis activist Spike Moss. Police say Beasley was hosting a party at the house. He got into an argument with another guest, who police say open fired and killed Beasley.

This May, a man showed up at the emergency room in HCMC. He told police he was driving on I-94 in Minneapolis when a shooter from another car fired into his vehicle. Police found bullets from the Glock at the scene on the highway.

In June, several gunshot victims showed up to a hospital together after a shootout. In a separate case in June, police responded to reports of dozens of shots fired near the Fourth Precinct headquarters and found several victims of what appeared to be another shootout. In a third case in June, a downtown surveillance camera recorded a group of men brawling. One of them pulled out a gun and fired several shots into the air. Shell casings found there matched the Glock.

The trail picked up again July 8, when the gun fell out of Jarvae Somerville's waistband in the bathroom of A & J Fish and Chicken.

Andy Mannix • 612-673-4036