Dean Matuu fatally stabbed his uncle last year in self-defense, Matuu’s lawyer told a jury in state court Tuesday.

Matuu, 20, is on trial for second-degree murder in the Jan. 24, 2015, death of his uncle, Frank Kapesi.

Deputy Chief Medical Examiner Rachel Lange testified Tuesday that Kapesi, 36, had one stab wound in his back and three in his chest, including one that punctured a lung and pulmonary artery. She said she removed what Honolulu police say they believe is the blade of a steak knife from Kapesi’s chest.

Defense lawyer Edward Harada told the jury that Matuu and Kapesi both emigrated from American Samoa, and they lived in a house on Aumakua Street in Pearl City with other relatives, all males. Harada said Matuu was the youngest and that he and Kapesi slept in the living room.

Harada said Matuu feared Kapesi, “an out-of-control raging bull” who terrorized everyone else in the house, having knocked out and sent another nephew to the hospital. And, he said, Kapesi was high on methamphetamine when he died.

On the morning of Kapesi’s death, Harada said, Matuu arrived home at about 4 a.m. and started making food for himself. He said Kapesi argued with Matuu and accused him of making noise and eating all the food, and wouldn’t leave his nephew alone. He said the arguing turned into a fight when Kapesi threw the first punch and Matuu defended himself.

“He was scared for his life,” Harada said of Matuu. “He was trying to make (Kapesi) stop, not to kill him.”

Another one of Kapesi’s nephews, Kapesi Kapesi, testified Tuesday that he was sleeping in his bedroom when the arguing woke him. He said when he went into the living room, he saw his cousin and uncle grappling. He said he got in between Matuu and his uncle but that then his uncle slammed Kapesi Kapesi to the floor and was on top of him.

Kapesi Kapesi said he got up and that Matuu took a swing at him, which he blocked. The hand he used to block the swing had been stabbed, he said. The next thing he remembered, he testified, is that his uncle was on the floor saying he couldn’t breathe and asking for help.

Prosecutor Dwight Nadamoto told the jury it was Matuu who started the fight with his uncle. He said Matuu killed his uncle because he was fed up with his uncle always picking on him. He said Matuu had no injuries from the confrontation but that Frank Kapesi had cuts and scrapes on his neck, face and legs in addition to the stab wounds.

Matuu is scheduled to take the witness stand Thursday.