Mark Cardilli Jr., 25, is led in handcuffs from the Cumberland County Courthouse in Portland on Dec. 27, 2019, after being found guilty of manslaughter in the killing of Isahak Muse. Jill Brady/Staff Photographer

A Portland man is appealing his manslaughter conviction for fatally shooting his sister’s boyfriend to Maine’s highest court, arguing the trial judge didn’t properly weigh evidence that he had acted in self-defense.

Mark Cardilli Jr., who admitted to shooting 22-year-old Isahak Muse during an argument in the Cardilli family home, was sentenced to 11 years in prison, with 3½ years suspended, in August 2020. In 2019, Muse was dating Cardilli’s sister, Chelsey, and a dispute over whether Muse could spend the night at the home in Portland led to a physical altercation, and then gunshots.

Cardilli is now appealing to the Maine Supreme Judicial Court. He argues, according to a summary on the court’s website, that “the trial court erred in failing to analyze whether Cardilli reasonably believed deadly force was necessary to prevent the victim’s use of unlawful, deadly force against him or others in the home.”

Isahak Muse Carl D. Walsh/Staff Photographer

Muse, a Deering High School graduate, visited the family’s Riverton home on March 16, 2019, intending to spend time with Chelsey Cardilli. An argument about whether he could stay at the house escalated to a verbal and physical confrontation. Mark Cardilli Jr., a U.S. Army veteran recently returned from a five-year stint, ran to his room, retrieved a pistol and fired at Muse, hitting him twice in the back.

Cardilli’s attorney could not be reached for an interview Saturday about the full context of his appeal argument. At the trial, the defense contended that Cardilli was acting to defend himself and his family. Prosecutors, who sought a murder conviction, questioned whether Cardilli could reasonably have feared for his life, noting that forensics experts from both sides agreed that Muse was shot in the back.

Race played a role in the case, though not in the conviction. The Cardillis are white and Muse was Black. The death of an unarmed Black man at the hands of a young white man claiming fear for his life sparked outrage in the community and comparisons to police violence against people of color.

Following a bench trial, Superior Court Justice Nancy Mills rejected arguments that the killing was racially motivated. She handed down a manslaughter conviction in December 2019 in lieu of the murder conviction that prosecutors and Muse’s family had sought.

Cardilli’s lawyers announced his intention to appeal immediately after the verdict was announced. Sentencing was delayed until August 2020 because of the coronavirus pandemic; Cardilli received 11 years of a maximum 30, with 3½ years suspended.

Prosecutors had sought an 18-year sentence, with 12 years in prison, whereas the defense asked for eight years, with four in prison. Four is the minimum in Maine for causing the death of another person with a firearm.

“I expect no one will agree with this sentence or like this sentence who is in the courtroom today,” Mills said at the time.

Oral arguments before the Maine Supreme Judicial Court are scheduled for 10 a.m. Tuesday. An audio stream is available here.