WHITE RIVER JUNCTION — A South Royalton man who shot and killed his estranged wife in front of family members is seeking to withdraw his guilty plea, arguing that he did not understand the terms of the deal and thought he was consenting to a much shorter prison sentence.

Frank Sanville pleaded guilty last year to second degree murder and aggravated assault with a deadly weapon in the shooting death of Wanda Sanville at her home in South Royalton. A plea agreement with prosecutors called for a prison sentence of up to 24 years.

But Sanville’s sentencing date has been held off pending a court ruling on his motion to withdraw his plea agreement.

Sanville “thought he was only going to serve four years — which was the minimum for the aggravated assault charge — and that he was not likely risking spending the remainder of his life in jail,” Sanville’s attorney, Rob Sussman, wrote in the motion to withdraw the plea.

Sanville filed his withdraw motion in June, eleven months after his July 2022 change of plea hearing in which he pleaded guilty to second degree murder, a lesser charge than the first degree murder felony count he originally faced. In exchange, the state agreed to drop two other charges of aggravated assault and one charge of being a convicted felon in possession of a firearm.

According to the motion to withdraw his plea, Sussman, the defense attorney, said that despite having on “numerous occasions” discussed the terms of the plea offer with his client, Sanville subsequently “made it clear that he never understood the terms of the plea” and had “based on discussion with a ‘jailhouse lawyer’ … believed he would be eligible for release after four years.”

“Jailhouse lawyer” is slang for a non-attorney — typically another inmate — who dispenses legal advice to inmates in prison.

Sussman noted that if Sanville — who is 76-years old and currently incarcerated at Southern State Correctional Facility in Springfield, Vt. — were to serve the maximum 24 years under the plea deal, “his current health makes it likely that he would pass away before” he would be eligible for release.

Sanville had been serving a furlough sentence for domestic assault against Wanda Sanville when he shot her in 2018.

“It must be noted that Mr. Sanville’s cognitive skills are extremely limited. He only has a seventh-grade education and cannot read or write,” Sussman wrote in his client’s motion. “Testing of his cognitive skills showed significant intellectual deficits, particularly for purposes of processing verbal information and applying it within a reasonable time.

“In short, it is not surprising that Mr. Sanville would misunderstand the terms of the offer, notwithstanding repeated attempts to ensure that he did,” the motion states.

Sussman declined to comment on Friday.

In the state’s response to the motion, Windsor County State’s Attorney Ward Goodenough dismissed Sanville’s claims that he did not understand the terms of his plea agreement and attached a transcript of 2022 plea hearing in which the judge questioned Sanville 21 times whether he understood that to which he was consenting and Sanville replied in the affirmative each time.

Goodenough wrote that Sanville’s motion is “driven by a single argument” that “rests entirely on a report from the defendant that at an unknown time he spoke with an unidentified ‘jailhouse lawyer’ who told him” that he would be eligible to go free in four years.

Further, Goodenough asserted, Sanville has never offered evidence in support of his “purported misunderstanding beyond a vaguely limited cognitive background” that “flies in the face of all the available evidence.”

He noted that over the years Sanville has engaged in numerous court proceedings — including past pleas on prior offenses — demonstrating his competency and signed multiple court documents in regard to his plea agreement in Wanda Sanville’s murder, which “repeatedly indicated to the court that he understood them.”

Goodenough on Friday declined to comment beyond the state’s motion to oppose.

A court hearing on Sanville’s motion to withdraw his plea agreement is scheduled in Windsor County Superior Court on Dec. 15.

John Lippman can be contacted at jlippman@vnews.com..