PORTLAND – A Vermont man changed his plea to guilty Tuesday for helping a New Hampshire couple who refused to pay their income taxes and holed up for months in their secluded home last year. A judge also postponed the trial until spring for three other defendants in the case.

Robert Wolffe, 50, of Randolph, Vt., pleaded guilty to aiding and abetting Ed and Elaine Brown and conspiring to interfere with the government’s efforts to arrest them. The three charges carry a combined maximum sentence of more than 53 years in prison and fines of up to $750,000.

Under a plea agreement, Wolffe did not have any charges reduced or received promises of a sentence reduction. But his cooperation with prosecutors could be a factor in their ultimate sentencing recommendation.

Wolffe was one of four people charged with helping the Browns after they skipped out on their tax evasion trial, where they were convicted of plotting to evade taxes on nearly $2 million.

The Browns barricaded themselves in their home in Plainfield, N.H., and vowed to fight to the death. Nearly nine months later, they were arrested without any bloodshed.

The Browns, now in prison, maintained that the federal income tax is not legitimate.

Wolffe was accused of lending the Browns his car, staying at their house in his camper and videotaping federal marshals.

At Tuesday’s hearing, Assistant U.S. Attorney General Arnold Huftalen and defense attorney Paul Garrity told Judge George Singal that Wolffe waived his right to appeal his conviction, but maintained his right to appeal his sentencing.

A sentencing date has not been scheduled.

Three other defendants – Cirino “Reno” Gonzales of Alice, Texas; Daniel Riley of Cohoes, N.Y.; and Jason Gerhard of Brookhaven, N.Y. – still face federal charges, including allegedly bringing weapons to the Browns at their home.

Singal agreed Tuesday to postpone the trial dates for the three. The trials had been scheduled to begin Monday, and will now start on March 24.

Defense lawyers said a delay was needed to give them more time to analyze DNA and computer evidence that only recently was made available to them. Huftalen told Singal that new evidence has been coming in as part of an ongoing investigation.

Riley, who is representing himself, told Singal he is concerned that he was indicted on two more counts last week. “I have a fear that the prosecution is being vindictive … because I didn’t take their plea bargain,” Riley said.

Singal is handling the case out of U.S. District Court in Portland because the federal judges in New Hampshire have pulled themselves off the trials after one of the judges received repeated threats following the Browns’ trial.