A maintenance worker inspecting a northeast Minneapolis apartment made a startling discovery last fall: a duffel bag full of guns stashed in a closet.

Police think the recovered handguns are linked to the theft of more than 30 firearms from a pawnshop in northern Wisconsin last year, a case that has piqued the interest of federal law enforcement agents, but remains unsolved.

The firearms were among the more than 700 handguns, shotguns, rifles and other semiautomatic weapons seized by police around the city last year, thanks to what authorities are calling a combination of old-fashioned police work and modern technology.

If the current pace of gun recoveries keeps up — 258 guns in the first four months of 2019 — police will top that total by the end of this year. Still, gun recoveries are down nearly a third over the past decade.

Minneapolis Police Commander Jason Case said police investigating gun crimes are making greater use of high-tech DNA analysis and forensic science, such as the National Integrated Ballistic Information Network at the federal Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), which lets investigators tap into a national database of weapons evidence that can help link firearms to crimes.

"I think our goal is always to use our analytics and our forensic evidence to always drive what we do," said Case, who heads the police division that includes the homicide, robbery and weapons units.

He said authorities are also concentrating their efforts on the relatively small number of individuals and locations that drive most of the violence in the city.

Data released by the department through an open-records request shows that roughly 40% of the 704 firearms recovered last year were seized in drug-related cases. Another 112 guns were recovered in connection with a homicide, robbery or serious assault. Sometimes, it's during a traffic stop, like earlier this year when officers pulling over a vehicle discovered a black Colt .22-caliber semiautomatic rifle, with an obliterated serial number and the word "killer" carved into its side. That firearm, like many others seized by police, appeared to have been obtained illegally.

Recovery hot spots

A closer look at Minneapolis police statistics shows a citywide downward trend in overall crime, despite year-to-year fluctuations in violence. At the same time, the number of crimes committed with firearms has been on the rise, according to the data.

Gun seizures jumped about 30% in both the North Side and Northeast police precincts compared with this time last year, Case said; they're down in the remaining three precincts.

In most cases, weapon-recovery hot spots overlap with blocks where gunfire is common, including the areas surrounding the 4th Precinct police station, the downtown entertainment district, the Little Earth housing project and near south Minneapolis' Corcoran Park.

But not everywhere.

Several areas with higher crime and violence — for instance, near the intersections of N. Colfax and 29th avenues, and N. Oliver and 35th avenues — didn't necessarily yield more guns, according to a Star Tribune analysis of available police data.

Handguns make up three out of every four firearms recovered, but police said they're also seeing more powerful weapons on the streets.

An earlier study by the Center for Evidence-Based Crime Policy at George Mason University found that in Minneapolis, about a quarter of illegal guns seized between 2012 and 2014 were capable of carrying a high-capacity magazine. For weapons used in shootings, almost half could carry a high-capacity magazine.

In October, police were called to an apartment complex across the street from the police union's headquarters in Northeast, after the worker found the bag of guns inside a room that's used to access the building's HVAC system, according to filings in the case. Peeking inside, he counted seven handguns.

Police say the firearms were traced to a burglary last July at an Ashland, Wis., pawnshop where more than 30 guns were taken. No arrests have been announced in the case, which is being investigated by the ATF.

Another of the stolen firearms — a Ruger .380-caliber handgun — was apparently recovered last September at a south Minneapolis gas station.

Burden on police

Some say the growing number of gun recoveries underscores the ease with which criminals can obtain firearms, skirting state laws that make it illegal for someone with a felony record to possess a gun.

The ATF's Kirk Howard, assistant special agent in charge of the agency's St. Paul field division, said every gun taken off city streets reduces the risks to residents.

"A rise in firearm recoveries doesn't necessarily mean a rise in crime. It could be a multitude of factors that contribute to a change in recovery numbers," Howard said in a statement. "More crime guns coming off the streets means increased safety in our communities and hopefully a correlated reduction in gun-related violent crime."

Others worry that law-abiding citizens are bound to be swept up in "stop and frisk"-style gun interdiction efforts, which research suggests can be effective when done right.

Maleta "Queen" Kimmons, who does outreach work with young men seeking to escape the gang life, argued that the burden of keeping illegal guns off the streets shouldn't just fall on police. "We need a community patrol, community response, so that the community is engaged and understands that the police can't solve all of this problem by themselves," she said.