Chelsey Cardilli testified Monday in her older brother’s murder trial that he told her that Somali people are gang members, that black people shot by police are always the ones at fault and that Muslims are terrorists.

Isahak Muse Carl D. Walsh/Staff Photographer

Mark Cardilli Jr. is charged with murder in the death of his sister’s boyfriend, Isahak Muse, 22, who was black and Muslim.

Cardilli, 25, has said he was defending himself and his home when he shot and killed Muse in March. His sister was the first witness called in the trial at the Cumberland County Courthouse, and she recounted her brother’s racist statements on the stand.

“What, if any, relevance do those statements have to Isahak?” Assistant Attorney General Leanne Robbin asked.

“That’s why he didn’t like him, and that’s why he killed him,” Chelsey Cardilli, now 18, said.

“I’m going to object, your honor,” defense attorney Matt Nichols said. “The last answer is speculation.”

The prosecutor rephrased the question at the judge’s direction. Because Cardilli waived his right to a jury trial, Superior Court Justice Nancy Mills will ultimately decide the verdict. Both sides used their opening statements to outline their theories of the case and the complex legal questions Mills will need to answer in rendering a verdict.

Prosecutor Leanne Robbin delivers the state’s opening statement Monday in the case against Mark Cardilli Jr. She said, “Shooting an unarmed guest in the back because he has overstayed his welcome is murder.” Brianna Soukup/Staff Photographer

The prosecutor described tension in the Cardilli household in the months before the shooting. Chelsey Cardilli, who was 17 at the time, was involved in the juvenile justice system and prohibited by the court from seeing her boyfriend. While her parents often told her she could not see Muse, they still allowed him to visit and even stay the night in the family’s home.

Robbin argued that Muse could not be considered an intruder under Maine law, and Cardilli did not have the right to use deadly force against him.

“Shooting an unarmed guest in the back because he has overstayed his welcome is murder,” Robbin said.

The defense said Muse was a negative influence on his teenage girlfriend, and the young couple routinely broke curfews and other rules.

Nichols said Muse was criminally trespassing by remaining in the house that night. He also accused Muse of other crimes, like assault and obstructing a 911 call. Those allegations speak to the state law on using deadly force in a person’s own home.

“The evidence is going to show in this case that Marky’s beliefs were reasonable, his conduct was reasonable and that he was justified in shooting Mr. Muse,” Nichols said, using a nickname for his client.

Attorney Matthew Nichols delivers the opening statement for the defense Monday in the case against Mark Cardilli Jr. Nichols said Isahak Muse was criminally trespassing in Cardilli’s house on the night he was shot. Brianna Soukup/Staff Photographer

The defense tried to block the testimony about past statements regarding racial and religious bias, but the judge allowed comments made in recent years to be admitted as evidence.

Chelsey Cardilli’s testimony was her first public comment on the case. She spent nearly three hours on the stand, answering questions from both sides about her relationship and the night of the fatal shooting.

She said she and Muse had plans to spend time together, so he came over against her parent’s wishes. Her family agreed he could stay until 1 a.m. Chelsey Cardilli said her mother then gave Muse permission to stay the night, but her brother confronted the couple at the curfew and demanded that Muse leave.

The resulting conflict involved the entire family and moved through the house. At one point, Cardilli went to his room and returned with a handgun. His sister said she did not see the fatal shots because she was yelling at her father to take the gun away from her brother, but she saw Muse drop to the floor.

Robbin played brief videos from a motion-activated security camera outside the house. One clip captured the sounds of a fight inside the house. In one clip, a man yelled, “Why are you hurting me?”

The prosecutor asked Chelsey Cardilli to identify the speaker.

“Ikey,” the girl said, tilting her head down so her long blonde hair blocked her face from view.

Nichols, the defense attorney, asked Chelsey Cardilli about her relationships with both her brother and her boyfriend, returning to her allegations of bias.

Justice Nancy Mills listens to opening statements Monday in the case against Mark Cardilli Jr. at the Cumberland County Courthouse. Mills will decide whether Cardilli is guilty of murder because Cardilli has waived his right to a jury trial. Brianna Soukup/Staff Photographer

“During the discussion, the arguments and physical alternations, Marky didn’t make any racial slurs or ethnic slurs, did he?” Nichols asked her.

“No,” she answered.

When the attorneys left their seats to speak to the judge in a conference at the bench, the siblings sat alone in the opposite sides of the courtroom, not making eye contact with each other. Later, Chelsey Cardilli sat in the audience and listened to other witnesses.

Dr. Mark Flomenbaum, the state’s chief medical examiner, testified that Muse died from two gunshot wounds to his torso. Those fatal bullets entered his back, Flomenbaum said, and the forensic evidence shows they were fired at close range. A toxicology report showed Muse had been drinking that night and had a blood alcohol concentration of 0.18 percent, which is over the legal limit for driving.

It is still unclear whether Mark Cardilli will take the stand, but the judge watched a recording of his interview with police in the early morning hours after the shooting.

On the tape, another Portland police officer questioned him about the evening, and he also described a chaotic confrontation. Cardilli said he went to his room twice during the fight, thinking about getting his pistol from its safe, and he only retrieved it on the second trip. When the officer asked why he did not call 911, Cardilli said he thought Muse was overpowering him and his father.

“He’s in our house, and he won’t leave,” Cardilli said at one point.

The officer told Cardilli that his family members also were talking to police.

“Are they doing all right?” he asked.

“Your sister’s not,” the officer said.