Mark Cardilli Jr., 25, is seen in a Portland courtroom on Dec. 9. Credit: CBS 13 | WGME

PORTLAND, Maine — A Portland judge convicted Mark Cardilli Jr., 25, of manslaughter Friday morning in the shooting death of his sister’s boyfriend earlier this year.

Cardilli was facing life in prison for murder after he admitted to shooting 22-year-old Isahak Muse during a fight that escalated at his family’s home in March. Cardilli testified that it was self-defense, and the case went to trial earlier this month. Maine law permits the use of deadly force in someone’s own home, and Cardilli said he opted for a bench trial because a judge was more equipped than a jury to interpret the complexity of that law.

“The state has proved beyond a reasonable doubt that Isahak Muse is dead, that [Cardilli] caused Mr. Muse’s death by shooting him with the glock and that [Cardilli’s] conduct was voluntary,” Superior Court Justice Nancy Mills concluded in her 52-page verdict of the case. “The state has not proved beyond a reasonable doubt that [Cardilli] acted intentionally,” which is required to convict a defendant of murder.

Mills did not issue an immediate sentence for Cardilli on Friday. The maximum penalty for manslaughter is 30 years in prison.

During a week of testimony, witnesses — including Cardilli’s own sister and mother — helped piece together the chaos that led Cardilli to shoot his sister’s boyfriend.

Muse was dating Chelsey Cardilli, who was 17 at the time, and some members of the family were not supportive of their relationship. Chelsey Cardilli testified that her brother, an Army sergeant, had a history of making racist and Islamaphobic comments about Muse, the son of Somali immigrants. She told the court that Cardilli had remarked that “Somali people are gang members” and “Muslims are terrorists.”

“That’s why he didn’t like him, and that’s why he killed him,” Chelsey Cardilli testified earlier this month.

Her parents often forbid her to see Muse but then still allowed him to visit and stay the night in the family’s home three to four times a week. On the night leading up to his March 16 death, Chelsey Cardilli asked her father if Muse could visit.

He refused.

When Muse arrived at the house anyway, the family agreed he could stay until 1 a.m., but after Muse stayed past that curfew, they said a fight broke out between him and the family.

Cardilli’s mother, Suzanne Cardilli testified that Muse slapped the phone from her hand when she attempted to call 911 as tensions escalated between him and her son. But that testimony is inconsistent with statements she told police after his death.

“I tried to call 911, but my phone — I don’t know why — didn’t do it.” Suzanne Cardilli said in police interviews played for the court this month.

Cardilli ran to his room and retrieved his handgun from a safe, according to witness testimony. He shot Muse in the back at close range, according to affidavits.

Muse’s death sparked outrage within Portland’s Somali and immigrant community.

“My brother didn’t do anything wrong and didn’t deserve the matter in which he died. He trusted and loved the Cardillis,” Muse’s older sister Awo Muse told the BDN during Cardilli’s trial earlier this month. “No one tried to do the right thing that night, and as a result of that, we have lost our baby brother.

She said it was “unfair and cruel to sit there at trial and relive” the events that led to his death.

“We just want justice for Isahak,” Awo Muse said. “May his soul rest in peace.”

Family and friends are raising funds to erect a drinking water well in Malawi in Muse’s honor, she said.