Minneapolis police are using the newest bullet-tracing technology to match bullets to different crimes around the city.

The high-tech system is a major advancement for solving gun-related crimes, and is already helping police with one of the worst mass shootings in city history.

“We try to figure out who’s pulling the trigger, who’s committing the crimes, who’s got information that they can share,” Deputy Chief Kris Arneson said.

The system is called National Integrated Ballistic Information Network, a national database of bullets and shell casings that looks like something straight out of a TV crime drama. Paired with the newest hardware, investigators can quickly link a single gun to crimes in different neighborhoods, cities, and even states.

Police are now using the technology to find an assailant in the 400 Soundbar shooting last August, in which at least one gunman opened fire inside the crowded downtown nightclub, wounding nine people — one of whom has since died of his injuries.

As police continue to investigate the Soundbar shooting, evidence collected at the scene and pumped into the new computer system is already linking the gun to at least eight other shootings, police said.

Each time a weapon is fired, signature markings are left on the bullet as it is squeezed through the chamber. The process of firing a weapon leaves a unique etching on each bullet, almost like DNA.

These markings are turned into three-dimensional images and plugged into the system and cross-referenced with thousands of other cases across the region.

Sometimes within minutes, the database shows whether the gun was used in any other crime.

If a gun is recovered at or near a crime scene, it is brought back to the lab and test-fired into a 6,000-gallon water tank so the bullets can be added to the archive, said firearms technician Tim Sittlow, who works at the crime lab.

Law enforcement agencies have long used the bullet-tracing process to solve crimes, but officials believe that the new system will dramatically speed the process. Once Minneapolis gets a new software upgrade, it will be the most advanced in the country.

The department’s downtown crime lab houses the new machine, which was paid for with the help of a $300,000 gift from the Federal Bureau of Alcohol, Tobacco, Firearms and Explosives.

It looks like a giant tower computer system.

Since 2002, the system has come back with more than 1,500 “hits,” connecting two or more gun crimes, police officials say.

In one case, a gun recovered at one scene was later found to be linked to at least 14 other shootings, officials said.

The system was designed to give local law enforcement agencies an advantage in dealing with low-level street violence that often escapes much police scrutiny.

Oftentimes, guns are frequently passed around and used in several separate shootings, police say.

One shortcoming

The system does have one giant shortcoming for crime solving. No matter how perfectly it can link bullets to crimes, it is no help in knowing who pulled the trigger.

Sittlow said that is where traditional detective work comes in. But the technology can be crucial in building cases against criminals.

If a suspect was found with the same gun, Sittlow said, it would give investigators a better idea of where to look for further clues and witnesses.

Jeffrey Magee, assistant special agent in charge of the firearm agency’s St. Paul office, said the effort is directly part of President Obama’s effort to curb violent crime, particularly in the wake a series of mass shootings around the country.

The president came to Minneapolis last winter expressly to call for tougher gun-control legislation, such as broader requirements for background checks.

At the moment, Minneapolis police and the Bureau of Criminal Apprehension are the only two law enforcement agencies in the state with the newest bullet-tracing hardware and software.

But more police departments are getting the technology every day.

And widespread use should expand the archive and widen law enforcement’s ability to link firearms to crimes.

In the past, forensic scientists were forced to try to link the same gun to different crimes by examining the markings under a microscope, a time-consuming process. Worse, with competing databases developed by the FBI and ATF, it was difficult for police departments to share information regionally, much less nationally.

New opportunities

The new technology also has created new opportunities.

Now two specially trained officers will respond to nearly all reports of shots fired, the type of incidents that often go ignored unless someone is wounded or killed.

They will collect evidence and canvass the neighborhood. And the database will continue to grow. “The two investigators will actually be investigating those crimes where they weren’t before,” said Arneson, with the police department.

Defense attorneys warn that the new technology leaves a wide legal gulf between which gun was used in the crime and who pulled the trigger.

Some legal experts cautioned that the technology could unfairly taint jurors in trail.

“Juries very much want to believe that scientific evidence is 100 percent accurate,” said Ryan Garry, a Minneapolis defense attorney. “And that’s the scary thing about scientific evidence: It’s not.”

Still, advocates say this is a giant step forward in helping law enforcement make sense of a maddening array of seemingly unrelated shootings.

“Do you still want to use 1970s techniques, where we have platinum suits and bell bottoms, or do we want to use 2014 technology?” Magee said.