Olathe ? A man who illegally voted in both Kansas and Arkansas while moving has pleaded guilty to a misdemeanor in a case that was among the first to be filed under a new state law that gives Kansas Secretary of State Kris Kobach the power to prosecute election fraud allegations.

Steven Gaedtke, 60, entered the plea Wednesday in Johnson County District Court, The Kansas City Star reported. He will pay the maximum $500 fine and court costs.

“He’s an otherwise law-abiding citizen who made a mistake,” Gaedtke’s lawyer, Scott Gyllenborg, said.

Gaedtke and his wife, Betty Gaedtke, 61, applied for advance voting ballots in Johnson County for the 2010 general election and submitted them while they were traveling back and forth over several months from Olathe to a home in Arkansas. During that time, they also voted in person in Arkansas, Trey Pettlon, the lawyer for Betty Gaedtke, said earlier.

Betty Gaedtke is charged with three misdemeanor counts related to unlawful voting. Pettlon said he will enter a not guilty plea for her Thursday.

“She maintains she’s innocent,” he said.

Steven Gaedtke is a Vietnam veteran who served in the U.S. Air Force, Pettlon said. Betty Gaedtke volunteers as a domestic violence educator. They built a cabin in the Arkansas Ozarks for their retirement.

Kobach’s office argues that it is protecting the integrity of elections. He said Thursday that pursuing such cases will deter people from double-voting and the guilty plea is significant because, previously, such cases weren’t prosecuted or defendants avoided fines.

“Five hundred dollars is not a slap on the wrist,” Kobach told The Associated Press. “That’s a lot of money in my book, plus he had to pay his attorney.”

Critics say voter fraud is rare.

Assistant Secretary of State Eric Rucker noted that during the 2015 legislative session, lawmakers increased several categories of unlawful voting from misdemeanors to felonies, which carry more severe potential penalties.

The cases against the Gaedtkes marked the start of Kobach’s promised crackdown on voter fraud. Cases from 2010 were chosen because of a five-year statute of limitations. The types of charges and penalties were subject to the laws at the time.

Kobach said his office plans to file additional election fraud cases by the end of the year. He is the only secretary of state in the nation with the authority to prosecute voter fraud cases.