BANGOR — Marshall Swan walked in handcuffs from the federal courtroom here Monday on his way to begin a 33-month prison term for falsifying five years’ worth of income tax returns and failing to report some $650,000 in income between 2006 and 2010.

The Chelsea contractor paid the $145,000 owed in back taxes Monday, but still must pay a $40,000 fine, which Justice John A. Woodcock Jr. calculated as equaling 10 percent of his net assets.

The prison term was at the top end of the federal sentencing guidelines in Swan’s case, and only three months shorter than sought by the prosecutor, Assistant U.S. Attorney Donald Clark, who said it was a case of “unconscionable greed.”

Woodcock told Swan, 56, that he opted for the top end of the guideline because Swan had obstructed justice in sending two men – Samuel Stone and William Dalrymple – to damage property belonging to Whitefield contractor Frank Monroe. Monroe was the main witness against Marshall Swan’s wife, Carole Swan, on charges that she extorted money from Monroe in return for his keeping a contract with the town of Chelsea, where she was a longtime selectwoman.

Woodcock said that attempt at witness intimidation struck “at the very heart of the judicial system.”

The damage to Monroe’s two pickup trucks and heavy construction equipment occurred late on Nov. 3, 2012, a few days after both Swans were indicted on numerous federal fraud charges and shortly after Marshall Swan met with the men on his son’s property.

Federal agents joined the investigation that led to Stone and Dalrymple.

At the sentencing hearing, Marshall Swan said he made mistakes, partly by spending so much time working on his various jobs and not with his family. He said he is saving the $47,000 profit from the recent sale of his home to pay workers’ compensation restitution for his wife.

Carole Swan is scheduled for a sentencing hearing next week on the same tax falsification counts, two counts of defrauding workers’ compensation and three counts of extortion as a town official.

Woodcock noted that the Swans’ case has split the town of Chelsea into two camps, those who support the Swans and can’t believe they would do wrong, and those who believe wholeheartedly in their guilt. “You split the community down its fault lines,” Woodcock told Marshall Swan, noting that some residents were in the back of the courtroom.

Just before Swan was led from the courtroom, he hugged and kissed his wife and two sons.

Carole Swan declined to comment.

After the hearing, Clark, the prosecutor, repeated some of the judge’s words, saying, “The victims here were all the people who pay their taxes.”

Marshall Swan’s defense attorney, Walter McKee, said afterward, “We were disappointed with the sentence and had hoped for significantly less. He accepted responsibility for what happened and is going to move forward from here.”

Betty Adams can be contacted at 621-5631 or at:

[email protected]

Twitter: @betadams