MONTPELIER — The Vermont Supreme Court has overturned the attempted kidnapping conviction of a Swanton man.

Harold D. Porter, Jr., had been sentenced to 30 years to life for allegedly attempting to kidnap a Burlington woman on Sept. 9, 2009.

The case was remanded for a new trial after the court concluded on Friday that Judge James Crucitti erred in allowing police detectives to testify about their conversations with other suspects who were not present to testify themselves.

The victim was walking along Colchester Avenue when a man got out of a truck and attempted to force her inside, according to court documents. He punched her and forced her to the ground. She screamed and eventually managed to get free and run to a nearby house.

The assailant fled in his truck.

Several witnesses described the vehicle and a CCTA bus driving past the parked truck before the incident had video footage of the truck.

Police showed the footage of the truck to a local Chevrolet dealer who identified the make and model. Only 20 Vermonters owned trucks of that color and make in the state.

Ten of those owners testified at the trial about their whereabouts at the time of the trial. The others did not. Instead, police investigators were allowed to tell the jury what they had learned from the other owners.

Porter, then 45, was the only owner without an alibi for the time of the kidnapping.

In their decision, the justices explained why the absence of the remaining drivers themselves at court was unfair to the defendant. “The reason for the exclusion is the same as for hearsay: the fact-finder has no basis for judging the reliability of the information because the credibility of the declarant cannot be challenged. This case illustrates the problem very clearly. A truck owner who testifies that his truck was elsewhere on the date of the crime can be cross-examined on issues of memory, mistake, actual knowledge, and other factors that may reduce the reliability of his statement. The same information passed along to an investigator in a private conversation cannot be challenged in any meaningful way because the declarant is absent,” wrote Justice Geoffrey Crawford on behalf of the court.

On other issues raised by the defense, including an eyewitness identification and an alleged failure by the police to preserve potentially exculpatory evidence, the court ruled in favor of the prosecution.

Porter was convicted of unlawful restraint and prohibited acts in 2001 in Franklin County.