PARIS — No new investigation will be conducted into the February murder of a 25-year-old landscaper following the acquittal of a suspect on Tuesday, state officials said Wednesday.

An Oxford County Superior Court jury found Agostino J. Samson, 23, not guilty after five days of testimony and slightly more than a day of deliberations. Samson had been charged with the bludgeoning and possible strangulation death of Scott Libby of Raymond. Libby’s body was found in his car in the early morning hours of Feb. 20 after a train struck the vehicle, which had been driven onto the railroad tracks off Barker Road in Bethel.

Assistant Attorney General Andrew Benson, the prosecutor in the case, said it would be “fruitless” to reopen the case.

“There was no information developed during the investigation that would suggest that anyone other than Agostino Samson killed Scott Libby, and my office and the state police still strongly believe that he’s guilty of murder,” Benson said.

Police determined that Samson, who worked for Libby’s greenhouse and landscaping business during the summer of 2008, met with Libby during the late evening of Feb. 19 to repay a loan in exchange for a watch and bracelet Libby had taken as collateral. Police said the exchange occurred at the Bethel Hostel, where Samson was staying, and was less than a mile from both a section of Westwood Road where bloodstains were found and the railroad tracks off Barker Road where Libby’s vehicle was hit by the train.

Benson argued during the trial that Libby’s DNA had been found on the watch, on bloodstains found on the exterior door handles of the hostel and on an alcohol swab found in the hostel’s trash. He said the swab also contained a partial DNA profile consistent with Samson’s DNA.

Defense lawyer Maurice Porter argued during the trial that none of the state’s evidence conclusively implicated Samson in the crime. The DNA on the swab could match thousands of people besides Samson, Porter said, and blood was not confirmed on the watch or inside the hostel.

Porter also argued that there was no evidence showing that Samson left the hostel or was inside Libby’s car. He criticized the police investigation, saying too much focus was placed on Samson at the expense of investigating other people, such as the other guests at the hostel or Libby’s acquaintances in the Boston area.

Porter also said police failed to scrutinize two unknown DNA profiles inconsistent with Samson that were found in Libby’s vehicle. Police testified that Libby’s killing likely occurred in his car due to several bloodstains there. Benson said there was no evidence that the profiles were those of Libby’s killer.

“If I were to check your car today, I would guarantee that I could find DNA, or the Maine State Police Crime Lab could find DNA, from 10 people who have ridden in your car,” Benson said. “I think that the charges are absurd, and they come up in any case,” he said of Porter’s criticism.

Lt. Brian McDonough, commanding officer overseeing the Southern Criminal Division of the Maine State Police, on Wednesday stood by the police investigation and Samson’s arrest.

“Our investigation was complete, it was thorough, and we’re very proud of the people who worked on it,” McDonough said.

Benson said police cannot again charge Samson with Libby’s death due to the constitutional protection against double jeopardy. He said he was disappointed in the jury’s decision but satisfied that they considered the evidence thoroughly.

“Obviously, I was not present in the jury room during the jury deliberations, and I’m not going to second-guess their decision,” he said. “Their view of the evidence was simply different from that of the state.”

[email protected]