Federal authorities announced a $10,000 reward Thursday in hopes of finding the masked perpetrator who broke into a northern Wisconsin pawnshop and hauled out more than 30 guns in a sack last summer.

A year later, about a dozen weapons have been recovered in Minneapolis and elsewhere, but the burglar remains on the loose.

The reward in connection with the break-in of Bay Area Pawn in Ashland, Wis., on July 30, 2018, was pulled together by the federal Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) in conjunction with the Ashland Police Department and the National Shooting Sports Foundation, the trade association for the firearms industry.

Also Thursday, the ATF released two fuzzy store surveillance photos of the suspect, which offered few clues about a description.

"We don't even know if the subject is male or female," said agency spokeswoman Ashlee J. L. Sherrill.

In October Minneapolis police were called to an apartment complex across the street from police union headquarters in Northeast, after a worker found a bag of guns in a room used to access the heating and cooling system, according to filings in the case.

This interior image shows a suspected burglar inside a northern Wisconsin pawnshop.

Peeking inside, he counted seven handguns, and police traced them to the Ashland burglary.

Another stolen firearm — a Ruger .380-caliber handgun — was apparently recovered in September at a south Minneapolis gas station, roughly 200 miles southwest of where the break-in occurred.

At least three of the guns were recovered in connection with a crime, Sherrill said.

Two involved juvenile suspects in Minneapolis and the other was a case out of Brooklyn Center. Sherrill had no specifics about those crimes.

Kirk Howard, acting special agent in charge of the ATF's St. Paul Field Division, said in a statement, "Around a dozen firearms have been recovered so far. We need the public's help in both the recovery of the remaining firearms as well as to identify the individual who is responsible for this crime.

"Stolen firearms are a big threat to communities because they often times fall into the hands of violent criminals who are prohibited from purchasing firearms legally," he said.

Minneapolis Police Department records from 2018 back up that contention. Data shows that roughly 40% of the 704 firearms recovered last year were seized in drug-related cases.

Another 112 were recovered in connection with a homicide, robbery or serious assault.

Anyone with information about the burglary can call 1-888-ATF-GUNS (283-4867) or e-mail ATFTips@atf.gov. Information can also be sent anonymously to ATF via the mobile Reportit app, which is available on Google Play and the Apple App Store, or by visiting reportit.com.

ATF is paying half the reward amount; the National Shooting Sports Foundation is contributing the other half.

This joint effort is part of a larger national cooperative initiative between the ATF and the foundation focusing on the theft of firearms from federally licensed firearms retailers.