Chelsea contractor Marshall Swan, convicted of five counts of filing false income tax returns covering the years 2006-2010, is scheduled to be sentenced Monday in U.S. District Court in Bangor.

Swan, 56, might take the witness stand at that hearing, which is scheduled for 10 a.m., according to his attorney, Walter McKee. If so, it will be the first time Swan has said anything publicly about the high-profile fraud case.

He did not testify during his three-day jury trial, which ended Oct. 2, and he did not testify at either of the two trials involving his wife, Carole Swan, a former member of the Chelsea select board.

McKee said Swan was not aware the tax returns were false since Carole Swan did all the office work and bookkeeping and was responsible for providing all the tax information to the preparer.

Carole Swan was convicted of the same income tax offenses — they filed their tax return jointly — as well as two counts of falsifying documents filed with the federal workers’ compensation program. She was also convicted at a separate trial of three counts of extortion for seeking bribes from Whitefield contractor Frank Monroe, who held a plowing contract with town of Chelsea while she was a selectwoman.

Carole Swan’s sentencing hearing is set for 1 p.m. Friday, June 13, in the same court.

Marshall Swan, who has no criminal record, faces a maximum of three years in prison for each of the income tax falsifications. In 2006 he pleaded guilty to a charge of domestic violence under an arrangement that allowed him to withdraw the plea after a year after completing counseling.

Assistant U.S. Attorney Donald Clark is seeking a longer sentence for both Swans, saying in court filings that Marshall Swan paid $200 to have two men “shoot up Monroe’s business” shortly after Feb. 29, 2012, when a federal grand jury initially indicted the Swans on numerous charges. Monroe initially went to police, saying Carole Swan was seeking kickbacks from him, which began the investigation that led to charges against the Swans.

On March 4, 2012, Monroe reported that tires on two of his pickup trucks were cut and door windows were smashed on his two excavators, possibly with a pellet or BB.

Evidence collected at the scene by Lincoln County Sheriff’s Office deputies led to the identification of William Dalrymple and another man, identified only as “CW,” an FBI confidential informant, according to the document in federal court.

The two men were identified as having committed a series of crimes together. Dalrymple died in March 2013.

In a defense sentencing memo, McKee said Marshall Swan denies the charge of obstruction of justice in connection with the shooting of Monroe’s vehicles. McKee reiterated that in an email on Friday, saying, “There’s no question that he strenuously denies the allegations made about the attack on Frank Monroe.”

In court filings, McKee says confidential informant “has an extensive criminal record and … has received promises and inducements from the government to testify against Marshall. The full extent of the agreement between the government and (confidential informant) will be addressed at the sentencing hearing.”

As part of his sentence, Marshall Swan is expected to be ordered to repay $145,000 in income and self-employment taxes due in those years, along with penalties and interest.

During the trial, Clark, told jurors that Marshall Swan underreported $650,000 in income during tax years 2006-2010.

“This was not a rounding error,” Clark said. “This was a sustained effort over five years to report 80 percent of his income. In three years, one of three dollars was not reported on his income tax.”

Clark said Swan reported earning $2.4 million over that five-year period but paid no income tax until 2010, when he paid about $2,000.

“In 2008, he qualified for the earned income tax credit, which is for poor people,” Clark said. “This is not a family that qualified for the earned income tax credit in 2008.”

Betty Adams — 621-5631 | badams@centralmaine.com | Twitter: @betadams