Mark Cardilli Jr., 25, is seen in a Portland courtroom on Monday. Cardilli is accused of fatally shooting 22-year-old Isahak Muse earlier this year at the Cardilli family's Milton Street home. Muse was dating Cardilli's sister. Credit: CBS 13 | WGME

PORTLAND, Maine — The trial of Mark Cardilli Jr., who is accused of murdering his sister’s boyfriend, 22-year-old Isahak Muse, in March, is nearing its conclusion.

The trial began with Chelsey Cardilli, the 18-year-old sister of the accused, whose searing testimony Monday described her older brother’s racist past statements, which included his beliefs 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 said Monday. Attorney Matt Nichols objected, calling her words speculation.

Chelsey Cardilli, like Muse, a Deering High School graduate, has joined community members in advocating for “Justice for Isahak Muse,” some of them wearing pins and T-shirts bearing the phrase while they sat quietly observing the week’s proceedings from the courtroom gallery.

Testimonies from her and Suzanne Cardilli — the mother of the accused whose account of the incident often differed from the one she originally gave — provided the week’s most dramatic moments. Plenty of other critical information has surfaced from forensics experts called to the stand, who have recreated what we know about the March 16 shooting in painstaking detail.

Muse, a Portland man whose parents came to Maine from Somalia, would have turned 23 on Tuesday. He had been Chelsey Cardilli’s boyfriend for about a year before his death.

Cardilli Jr. fired three bullets at Muse during an altercation at the family’s home at 107 Milton St., two of which entered the victim from the back, according to multiple forensics experts including the state medical examiner. He intends to prove that he acted in self-defense. He has waived his right to a jury, and the case will be decided by Justice Nancy Mills.

The courtroom could stand to hear testimony from Mark Cardilli Sr., the accused’s father, on Friday morning before Justice Mills takes the case under advisement before a final verdict. He is slated to appear before the courtroom but the defense has pushed to submit a prepared deposition recorded in November in his place. There has been no decision about whether Cardilli Jr. would testify, according to a spokesperson from the attorney general’s office.

Justice Mills said Friday morning that she would reach a verdict sometime next week.

Here’s what else we know

On Thursday, the defense called forensic specialist Jonathan Arden, trying to determine the angle at which Muse was standing when he was shot. Arden said he had “no material disagreements” with Dr. Mark Flomenbaum, the state’s medical examiner who determined that Muse was shot from behind with the muzzle of the gun pressed against his jacket, but questioned whether a third bullet, which seemed to graze Muse’s hand and brow, had also been fired from behind.

It was also determined Thursday that Muse had a blood-alcohol level of 0.18 at the time of death, though no other substances (besides caffeine) were in his bloodstream.

On Wednesday, Suzanne Cardilli struggled to remember details related to the incident when asked by prosecutors, telling the courtroom that Muse had prevented her from calling 911, a detail she did not tell police when directly questioned hours after the event.

Cardilli Jr.’s mother said that Muse had permission to be there, but refused to leave the house at the hour determined by her and her husband after being told multiple times.

In an effort to justify the use of lethal force by Cardilli Jr., the defense opened the day Wednesday hearing testimony from the Cumberland County Sheriff’s office, which had listed Isahak Muse as 6’0” and 150 pounds. The state’s medical examiner said Muse was 5’9” and 139 pounds at his time of death.

Cardilli, who is 5’7”, said in interviews with police that he feared that Muse would physically overtake him and his father as they attempted to remove him from the house.

On Tuesday, it was revealed that Cardilli Sr. told his son that he did not know that the pistol used to shoot Muse was real.

“I thought you were trying to scare him,” Cardilli Sr. had said to his son in custody immediately after the event, as recounted over video evidence played for the court.

“I wasn’t going to play around anymore,” Cardilli Jr. told his father.

Also on Tuesday, the court heard testimony from Staff Sgt. David Gutierriez, who had been stationed with Cardilli Jr. in Fort Drum, New York. Describing Army life, Gutierrez said Cardilli Jr. — whom he called a friend — wasn’t an “alpha male” like others they were stationed with but “knew the way to posture himself so that he wasn’t an outsider.”

Gutierrez also downplayed the element of racism as a role in the case, saying that it “wasn’t a factor” in Army life.

“None of those factors mattered at all — race, culture, religion,” said Gutierrez, who said that soldiers identified as “infantrymen first.”

“The system is not such that you could get away with it,” he said.

Gutierrez also said that Cardilli Jr. had been trained in nonlethal force and de-escalation but that such training “doesn’t occur often enough” in the Army.

During a dispute late in the day Tuesday, defense attorneys attempted to establish whether Muse had put the hood of his sweatshirt up the night of the event. Chelsey Cardilli said multiple times that he had not been wearing the hood that evening, or during the altercation, in her account to police hours after the event. But after further questioning, Chelsey said it was possible he had “maybe” put the hood up during the altercation.

The issue of whether Muse was wearing the hood of his sweatshirt up over his head is one of several tactics that the defense has relied on to bolster the argument that Cardilli Jr. acted in self-defense.

On Tuesday, Kimberly James, an evidence technician at the Maine State Prison crime lab, said that an analysis of gunpowder residue suggested that the weapon used by Cardilli Jr. to shoot Muse, a glock pistol, had to have been fired while making contact with Muse’s jacket, echoing testimony from the state’s medical examiner yesterday.

The defense made a motion to acquit Cardilli Jr. on lack of evidence Tuesday afternoon, an attempt which failed.

“It is murder in the State of Maine to shoot someone who had been invited to the house in order to get them to leave,” attorney Leanne Robbin said during the motion.