The Minnesota DFL Senate campaign was hit with a $100,000 fine Tuesday for improperly coordinating 2012 campaign mailings with candidates.

The result of an investigation and settlement talks that lasted more than a year, the fine imposed by the state campaign finance agency is one of the largest levied in Minnesota for campaign violations. The penalty stems from candidates and the party committee violating rules that ban coordination between independent spending and what is controlled by a candidate.

Senate Majority Leader Tom Bakk and DFL Party Chair Ken Martin said they were pleased the long-running complaint is closed but noted that they disagreed with the conclusion.

"Ultimately, it is best to set this distraction aside and allow our members to focus on governing," Martin said.

The Campaign Finance and Public Disclosure Board found that the DFL Senate committee and 13 candidates, 11 of whom now sit in the Senate, coordinated photos for mailings that the committee sent out. For the mailings to be legal independent expenditures, the Senate campaign should have prepared the mailings without any input from the candidates. Instead, the agency reported, the candidates were intimately involved in making the photos for the mailings look good.

"Each candidate's involvement consisted, at a minimum, of actively participating in a photo shoot," the board found. In many cases, the candidates also helped arrange locations, volunteer models and even brought changes of clothes "to provide a variety of looks."

The photos of candidates modeling in cornfields, classrooms and offices were "a prerequisite" for the Senate campaign being able to create the mailings, the board said.

"The cooperation and full participation of candidates in a key part of the process … destroyed the independence of the resulting communications," the board's final conclusion said.

The board has levied only two fines of equal or greater size in the past 11 years: It fined then-gubernatorial candidate Tim Pawlenty $100,000 for coordinating a 2002 television ad with the Republican Party, and it fined the national 21st Century Democrats $190,000 for failing to disclose the spending it used to influence Minnesota's 2004 election.

GOP reaction

Former Republican Party Chairman Pat Shortridge, who filed the initial complaint about the DFL matter in October 2012, said the violation was clear from the start.

"As I said at the time we filed the complaint, these were staged photo shoots that were so clear-cut that they practically define illegal coordination," Shortridge said. He said that the DFL's illegal activity contributed to the defeat of Republican candidates in 2012.

Senate Minority Leader David Hann, R-Eden Prairie, put it even more bluntly: "The question really needs to be asked, 'Would they have won the majority if they hadn't cheated?' "

DFL Sen. Jim Carlson of Eagan, one of the senators who participated in a photo shoot, said he had no intention of cheating.

"Everyone was under the same misunderstanding," Carlson said. He said while he sat for the photos, he did not see the mailing produced from them until a friend received one in the mail.

"The candidates assumed that the Senate caucus party unit would not request something that would lead to contribution and spending limit violations," the board wrote. "This reliance was misplaced."

The agency's settlement highlights photo shoots and mailings sent to support DFLers Carlson, Alan Oberloh, Vicki Jensen, Tom Saxhaug, Kevin Dahle, Kent Eken, Melisa Franzen, Laurie McKendry, Matt Schmit, Gregory Clausen, Alice Johnson, Susan Kent and Lyle Koenen. All but Oberloh and McKendry won their elections last year.

Although the DFL's legal counsel settled the matter and the Senate campaigns cooperated with the board, Bakk insisted on Tuesday that the 2012 mailings did not violate the law.

"We continue to maintain that our candidates and the caucus campaign committee complied with all campaign finance laws. Although we respectfully disagree with the board's position, we believe it is better to put this matter behind us," said Bakk, DFL-Cook.

Minnesota Republican Party Chairman Keith Downey, who lost a Senate race to Franzen last year, drew a different conclusion: "They cheated, they won, but at least they are being held accountable now."

Rachel E. Stassen-Berger Twitter: @RachelSB