A Mississippi businessman whose construction contracts at the troubled Orleans Parish Prison drew attention from federal investigators pleaded guilty Tuesday to failing to pay more than $150,000 in taxes.

Kendall Marquar, of Waveland, faces up to a year behind bars and a $100,000 fine for failing to report more than half a million dollars of income to the Internal Revenue Service between 2007 and 2009, according to court documents. A large portion of the unreported income, prosecutors said, stemmed from work performed by Marquar’s company, K&D Earthworks, a maintenance and construction vendor for the Orleans Parish Sheriff’s Office.

Under the terms of his plea agreement, Marquar has agreed to pay $156,941 in back taxes to the IRS. His sentencing was set for Sept. 9.

Marquar, 36, has long been on the radar of federal agents probing questionable contracting at the Sheriff’s Office. The investigation yielded charges against John Sens, a former purchasing director and fundraiser for Sheriff Marlin Gusman, and Col. Gerard Hoffman, the sheriff’s former maintenance director.

Marquar was close to Billy Short, the former chief deputy, who, before his October 2011 death, was a central figure in the FBI probe. Short was never charged with a crime.

Marquar facilitated the permit for a pool built at Sens’ home in Waveland that later figured into Sens’ guilty plea to bribery and bid-rigging charges. Another jail contractor, Richard Molenaar III, who also pleaded guilty in the scheme, admitted paying for the pool, which cost roughly $25,000.

Along with his ownership of K&D Earthworks, Marquar was listed as a principal in Gulf State LLC, a company the Sheriff’s Office called on in 2012 to make a series of questionable renovations to the now-shuttered House of Detention. The repairs, totaling at least $213,000, were authorized for a controversial jail facility that Gusman closed just weeks later. The 11th-hour renovations were apparently part of an unsuccessful effort to improve the decrepit facility before a visit by federal authorities separately investigating the jail’s oppressive conditions. A federal judge has since ordered sweeping changes at OPP.

Marquar’s plea agreement requires he “submit to interviews whenever and wherever requested by law enforcement authorities” and that he “assist the government with regard to the investigation and prosecution of criminal conduct of any other person.”

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