Lt. Bob Kroll, the president of the Minneapolis police union, again found himself in political hot water this week when the DFL Party accused him of circumventing federal election law by appearing in uniform at a re-election rally for Republican U.S. Rep. Erik Paulsen.

A news release circulated on Thursday afternoon featured a photo of a steely-faced Kroll standing next to Paulsen at a campaign event in Wayzata earlier in the day. That he appeared in full uniform, the party argued, is a violation of the Hatch Act, which prohibits state and local officers from engaging in partisan political activity.

"Erik Paulsen and Bob Kroll have made it all too clear that they'll go to extreme lengths to further their own personal political agendas, even if it means violating federal law," the release said. "We've come to expect this kind of misbehavior by Kroll, but it's disturbing that Erik Paulsen would go along with these antics."

A spokesman for Paulsen's campaign said that he could not comment because he hadn't yet seen the release. Kroll remained defiant, accusing Democrats of political opportunism and insisting in an interview that he was acting "not as a representative of the MPD, but in my official union capacity."

He added that he had notified police Chief Medaria Arradondo via e-mail of his intention to appear at the event. A police spokeswoman said that in the department's view, Kroll's actions were not inappropriate.

"If they want to bring federal criminal charges against me, be my guest, but they never said anything in the past about our endorsements of the DFL," he said, adding that status as federation president affords him certain protections under the current union contract.

Paulsen is being challenged for his congressional seat by first-time Democratic candidate Dean Phillips.

The outspoken Kroll is in the final year of his second two-year term as head of the Police Officers Federation of Minneapolis, which represents the 900 or so city and park police officers. As president, he collects about $29,000 a year in salary.

Last month, he drew criticism from Minneapolis Mayor Jacob Frey and several City Council members after he and several other uniformed officers appeared in a campaign mailer from Republican gubernatorial candidate Tim Pawlenty calling for a crackdown on illegal immigration.

Frey at the time questioned whether the flier violated city policies: one, barring the unauthorized use of the Minneapolis Police trademark and another prohibition on officers other than the union president or a designee appearing in a political advertisement.

Kroll countered by arguing that all eight officers pictured were authorized to appear under a provision that allows elected union officials or designees to participate in political promotions.

In 2016, then-Chief Janeé Harteau ordered Kroll to stop wearing his uniform during media interviews while representing the union, after he angered city officials by calling the Minnesota Lynx attendance "pathetic." Kroll said he was not disciplined as a result of the incident; instead the matter was sent to be "coached."

Star Tribune staff writer Andy Mannix contributed to this report. Libor Jany • 612-673-4064 Twitter:@StribJany