A bill protecting Minnesotans who report unlawful conduct from retaliation in the courts has flown through the Legislature and is awaiting Gov. Mark Dayton's signature.

The Senate version of the bill, the result of a Washington County confrontation over campaign signs, breezed through the House on Thursday on a 130-0 vote. It amends an existing law to ensure legal immunity for anyone reporting crimes and promoting other "public participation" activities such as peaceful demonstrations.

"I believe it's good public policy to protect the citizenry cooperating with law enforcement, and I'm pleased the House and Senate felt the same," said Keith Mueller, a resident of the Washington County rural city of Grant who was sued after a campaign sign dispute.

Grant is a city of about 4,100 residents just west of Stillwater.

Mueller said Minnesotans now "are better protected from frivolous lawsuits aimed at silencing one's testimony."

The legislation stems from a controversy that began in 2010 when Jeffrey L. Nielsen was charged with disorderly conduct, theft and two traffic offenses after he was accused of taking campaign signs belonging to Steve Bohnen, who was campaigning for the Grant City Council.

Nielsen was convicted of disorderly conduct, while the other charges were dropped. He then sued Mueller, who had reported him, along with Bohnen and Washington County. The lawsuit led to years of courtroom battles and hundreds of thousands of dollars in legal bills for the defendants, who ultimately were able to get their cases dismissed.

The bill passed Thursday further clarifies a state law intended to prevent intimidation of Minnesotans performing their civic duty. Mueller and Bohnen testified at the Legislature that the law was insufficient and needed clarification.

The amended law now explicitly shields people who seek law enforcement assistance and who report suspected crimes. It also specifically includes citizen appearances before a zoning board regarding a real estate development project, communications with an elected official concerning a change in law, and complaints filed with a government entity regarding safety, sexual harassment, civil rights and equal employment rights.

The bill also will help deter frivolous lawsuits by allowing judges to "liberally" apply its purposes and intent — which Mueller said will hold attorneys accountable to ensure that "citizens are not wrongfully blown over in an attempt to satisfy their wealthy client."

The bill had support from the Minnesota Sheriffs' Association, the Minnesota Association of Justice and other law enforcement agencies and organizations.

Rep. Kathy Lohmer, R-Lake Elmo, who shepherded the bill in the House, said Friday that "it was a really good bill" that closed loopholes in state law.

"People should be able to feel free to report crimes to police," she said.

Staff writer Abby Simons contributed to this report. Kevin Giles • 651-925-5037