AUGUSTA, Maine — The Maine Supreme Judicial Court is set to hear the appeal of a 23-year-old man sentenced last June to three life terms in prison for killing three people in a rural home in Amity in June 2010.

Attorneys for Thayne Ormsby hope to have his conviction overturned because they say not only that his Miranda rights were denied, but also that they were denied a change of venue before the case was heard in southern Aroostook County, where the murders took place.

James Dunleavy of Presque Isle, one of two attorneys representing Ormsby, said Tuesday that the hearing on his client’s appeal will take place the week of Sept. 9-12. The court has not set an exact date or time.

Deputy Attorney General William Stokes also confirmed Tuesday that the court had given the prosecutor’s office the September schedule, though not an exact date for oral arguments.

“After oral arguments, we could have a decision in 60 to 90 days,” Stokes said.

Ormsby was convicted on April 13, 2012, in the stabbing deaths of Jeffrey Ryan, 55, Ryan’s son Jesse, 10, and Ryan family friend Jason Dehahn, 30, all of Amity.

The three victims were found dead on June 22, 2010, about 27 hours after the killings were committed at the elder Ryan’s home on U.S. Route 1 in Amity, according to police. All three died of multiple stab wounds.

There are several points at issue during the appeal, including statements Ormsby made to police on July 2, 2010, at a police station in Dover, N.H.

Ormsby’s attorneys claim that his Miranda rights were violated and his statements were involuntary.

During a July 2011 court hearing, Maine State Police Detectives Dale Keegan and Adam Stoutamyer testified that Ormsby was repeatedly read his Miranda rights before and during the interview. Keegan said Ormsby professed innocence until confronted with evidence from the crime scene, and then admitted guilt and wrote out a confession for police. Keegan testified that he read Miranda rights again before Ormsby wrote out his confession.

In the appeal, attorneys are focusing on points of the July 2, 2010, confession during which Ormsby said he would have to “plead the Fifth” to some questions, and at one point said, “Perhaps I do need a lawyer.”

Despite his statements, Ormsby kept talking and answering questions for police, according to testimony, and never requested that the interview cease or he be provided an attorney.

Dunleavy and Ormsby’s other attorney, Sarah LeClaire of Presque Isle, also said in appeal documents that the trial court erred in denying their motion for a change of venue. The attorneys filed for the change in February 2012, two months before the trial, but the motion was denied in Aroostook County Superior Court in Houlton during jury selection.

Ormsby entered pleas of not guilty and not guilty by reason of insanity to the charges. Because of the dual pleas, Ormsby was tried in two phases before Justice E. Allen Hunter in Superior Court in Houlton. He was first found guilty of the murders on April 13, 2012, and then criminally responsible for his crimes on April 19.

Ormsby also was found guilty of arson for burning Jeff Ryan’s truck after he stole it from the murder scene. He was sentenced to 15 years in prison for that crime, and it is being served consecutively with the life sentences.

Ormsby, an Ellsworth native, moved in the weeks before the murders to live with Robert and Joy Strout in Orient, just about a mile from the crime scene. Robert Strout told Ormsby that Ryan was a drug dealer, though no evidence ever supported that claim.

Strout eventually confessed to hindering apprehension and arson for his role in helping Ormsby conceal evidence in the murder investigation. In May 2012, Strout was sentenced to serve four years in prison on those charges and on an August 2011 drug offense.

Dunleavy said Tuesday that he and LeClaire were still discussing the upcoming oral arguments and that he was not prepared to comment on whether both attorneys would attend the September hearing.