Relatives describe Charly Hernane as introverted, a loner, unsociable, withdrawn and even scary, prosecutor Darrell Wong told a state jury Wednesday in opening statements in Hernane’s murder trial.

Hernane, 29, is accused of killing his adoptive mother, Teresita Dumalan Hernane, on May 11, 2011, in the Kalihi home they shared with relatives.

Wong said none of Charly Hernane’s relatives were able to talk to him and only he knows why he stabbed his mother on the side of her face and neck with a butcher knife.

"What goes on in the mind of a man who spends his entire day in the bedroom that he shares with his adopted mother, who has no job, he has no friends, he has no hobbies, no interests," Wong said.

He said Hernane left the bedroom at night and went to an outside stairwell to smoke.

Teresita Hernane’s 17-year-old niece found her aunt’s body on top of a blood-soaked bed with the butcher knife on the floor nearby.

Police found Hernane at Kalakaua District Park nearby, his shirt and shorts stained with his mother’s blood.

In the early morning hours before the niece found the body, Wong said, a neighbor heard the voice of a man speaking angrily in English and Filipino, then what sounded like a metal object hitting the ground.

According to an autopsy, Teresita Hernane, 56, died of a stroke and injury to her jugular vein from a stab wound to her face.

Forensic pathologist Dr. Kanthi De Alwis, who performed the autopsy, testified Wednesday that the stroke could have been precipitated by the knife attack.

Teresita Hernane had hypertension and was undergoing regular dialysis treatments.

Defense lawyer Alan Koma­gome told the jurors if they believe it was Hernane who caused the fatal injuries to his mother, to find him guilty of murder they need to determine that he did so with the knowledge or intent to kill.

"At the end of this case, I think you will find that those injuries are not consistent with someone having an intentional and knowing state of mind when it comes to causing the death of (Teresita)," Komagome said.

He also told the jurors they will be asked to consider finding Hernane guilty of manslaughter instead of murder.

Wong said Teresita adopted Charly, her husband’s nephew, in the Philippines. She moved to Hawaii in 1994 and later brought Charly Hernane to live with her.

Relatives said that after dropping out of Farrington High School, Charly Hernane returned to the Philippines for drug rehabilitation, returning to Hawaii about four years ago.