PORTLAND (AP) – An Augusta man is seeking a new trial by claiming his hospital room confession was illegally obtained while he was being questioned about the murder of his mother-in-law.

David Grant’s attorney, Christopher MacLean, told the Maine Supreme Judicial Court Tuesday that detectives didn’t read Grant his Miranda rights – his rights to remain silent or to have legal representation – when they questioned him about the killing of Janet Hagerthy.

Grant, 57, is serving a 70-year sentence in the November 2004 slaying of Hagerthy at her home in Farmingdale. She was choked, beaten and stabbed to death following an argument over how to start a snowblower.

If the law court agrees Grant’s rights were violated, he could be eligible for a new trial.

Grant was questioned by detectives for several hours over two days while he was in a Bangor hospital for emergency surgery after he was found in his pickup truck in a ditch in Palmyra, repeatedly stabbing himself in the neck with a knife.

“If he was in custody, his rights were violated and the confession needs to be thrown out of evidence,” MacLean said. “It would earn him a new trial.”

Assistant Attorney General Donald Macomber told justices they should uphold an earlier finding by Superior Court Justice Kirk Studstrup that Grant was not in police custody when he was questioned, he was simply recovering from surgery for the stab wounds.

Associate Justice Donald Alexander asked MacLean if the confession even played much of a role in the trial given the other evidence against Grant.

“Assuming we agree with you about the custody issue, so what? Isn’t the evidence overwhelming? There was blood in the back of the truck,” he said.

Chief Justice Leigh Saufley agreed the case against Grant was compelling and questioned why prosecutors used Grant’s confession.

“Why is it, in a case where the evidence appears overwhelming, why did the state push to admit the confession?” she asked.