The state’s highest court has upheld the manslaughter conviction of a Portland man who shot and killed his sister’s boyfriend in 2019.

The appeal centered on the legal requirements for using deadly force in self defense.

Isahak Muse Carl D. Walsh/Staff Photographer

Mark Cardilli Jr., now 26, admitted to killing 22-year-old Isahak Muse during a fight at Cardilli’s parents’ home in Portland’s Riverton neighborhood, but he said he was defending himself and his family. Muse was visiting his girlfriend that night, and the conflict started as a disagreement over whether he could spend the night. The entire family was involved in a verbal and physical altercation before the shooting.

Cardilli initially was charged with murder, but Superior Court Justice Nancy Mills found him guilty of the lesser offense after a bench trial, and he appealed that conviction to the Maine Supreme Judicial Court. He is currently serving 7½ years in prison.

“Even if Cardilli had an actual belief that Muse was about to use deadly force by taking control of the gun that Cardilli brought into the chaos – a belief not asserted by Cardilli at trial – the court found that any such belief was objectively unreasonable,” Justice Ellen Gorman wrote in the court’s opinion.

The attorneys who represented Cardilli in his appeal did not respond to an email about the case Thursday.

Assistant Attorney General Leanne Robbin, who prosecuted the case, said she was pleased with the court’s opinion.

“We are pleased that the Court agreed that a homeowner cannot use deadly force against an unarmed guest who merely overstays his welcome,” she wrote in an email. “The Legislature has clearly defined the circumstances under which deadly force may be used against another person. Every person who owns a gun in Maine has the responsibility of knowing the legal standards governing the use deadly force.”

Mills ruled that the state did not prove that Cardilli was not acting in self defense, and that his belief that he needed to shoot Muse was unreasonable. That conclusion supported neither a murder conviction nor an acquittal, and the result was the guilty verdict for manslaughter.

One question raised in the appeal was whether a reasonable person would have considered Muse to be a guest or an intruder at the time of the fatal shooting, a key question in the law regarding deadly force. The Supreme Judicial Court agreed with Mills when she said Cardilli was unreasonable to treat Muse as a trespasser. He knew his parents had allowed Muse to stay for hours that night, Gorman noted in the opinion.

“Contrary to Cardilli’s assertions, there was competent record evidence to support the court’s determination that Cardilli’s belief that Muse was not licensed or privileged to enter the Cardilli home or that he surreptitiously remained therein was objectively unreasonable. … Even if Muse overstayed his welcome at the Cardilli home, as he clearly did, that fact is irrelevant,” Gorman wrote.

The Cardillis are white, and Muse was Black. Since the first days after the fatal shooting, the role of racism was a constant question.

While police investigated the incident, local Muslim leaders voiced their concern that it was a hate crime. When Mills set bail at $50,000 and allowed Cardilli to wait for his trial at home, protesters questioned whether a Black defendant would have received the same treatment. And when Chelsey Cardilli, Muse’s girlfriend, took the stand at the trial, she said her brother had made racist statements about Muslims, Somali people and Black people.

In her ruling, Mills wrote that she did not find the young woman’s testimony to be credible, and her verdict did not otherwise raise those allegations. In the appeal, neither side discussed racism as a factor in the case.

Cardilli is serving his sentence at the Maine Correctional Center in Windham. He faced a mandatory minimum sentence of four years in prison because he used a firearm to cause the death of another person. The maximum penalty for manslaughter is 30 years.