Two members of a family responsible for a Twin Cities-based cellphone theft ring pleaded guilty to a federal charge on Monday.

Talal Mustafa and Edwan Mustafa pleaded guilty to conspiracy to engage in interstate transportation of stolen goods for their participation in a national crime syndicate, an assistant United States attorney handling the case said in an email.

The University of Minnesota Police Department assisted the FBI and several other agencies last year in busting the national crime ring.

The University’s campus and surrounding neighborhoods saw a spike in cellphone thefts around the same time the crime ring operated in fall 2013. University police Deputy Chief Chuck Miner told the Minnesota Daily in September that UMPD didn’t know if the Mustafa family was involved in those thefts.

Assistant U.S. attorney Steve Schleicher said in an email that the two also pleaded guilty to a tax charge. Several pleas in the case are set for this week, he said.

In some cases, members of the crime ring obtained the phones through violence or burglary, according to an August 2014 FBI press release.

Authorities told the Daily last fall that one low-level associate may have stolen over $2.7 million in phones over six years.

The Mustafas owned mobile device stores throughout the metro area. They used those stores to knowingly buy and sell phones that had been stolen or illegally obtained, according to the charges against them.

Members of the crime ring signed up for family or business cellphone plans with stolen identities, according to court documents.

Members then purchased smartphones and tablets at discounted prices using those identities and sold the devices back to the family, according to the FBI’s statement.

UMPD officers spent about 10 months working with other agencies to bust the ring.

University police Chief Greg Hestness said in the release the school’s police worked for hours to control the robberies.

“Without addressing the underlying criminal enterprise creating a market for these phones, we were not doing everything possible to protect our students,” Hestness said, “UMPD was honored to contribute to this critical major investigation.”