Police arrested a 31-year-old man Wednesday on suspicion of murdering a family member at a home in Pearl City.

The Honolulu Medical Examiner’s Office did not release the victim’s name, but neighbors identified him as Stanley Yamada.

Police responded to a call to check on the welfare of a 53-year-old man and found him unresponsive with suspicious head injuries in his residence at 98-1367 Hoohonua St. at about 10:30 p.m. Tuesday. Emergency Medical Services personnel responded and pronounced him dead.

Lt. Deena Thoemmes of the Honolulu Police Department’s Homicide Detail said the victim and suspect are reportedly family members. The suspect was found inside the home and police arrested him on suspicion of second-degree murder and criminal contempt of court.

Yellow tape was stretched across the front of the home Wednesday morning as police continued their investigation.

Yamada’s next-door neighbor, who declined to be identified, said he heard a woman crying Tuesday night and went outside to find multiple police vehicles lined up in front of the Yamada home.

The neighbor said that since the 1970s he grew up next to the Yamada family, and played basketball in the driveway with Stanley Yamada, who he described as a selfless, humble and warm-hearted person. “To me, he was a person filled with aloha,” the neighbor said.

He referred to Yamada as his “big brother,” a friend he often confided in.

Residents in the close-knit neighborhood said Yamada lived at the home with his mother. She is staying with another family member in the wake of Yamada’s death.

Another neighbor who lives across the street said he had known Yamada — who worked for Hawaiian Airlines — since Yamada was a young boy. The resident said Yamada often helped his neighbors tend to and mow the grassy strips on the sidewalk fronting their homes. “Stanley’s a good boy,” the resident said.

Neighbors said the suspect did not reside with Yamada but visited periodically. They described the suspect as unstable and observed him at times mumbling to himself or having verbal outbursts. One neighbor who did not give her name said the suspect is Yamada’s nephew.

Court records indicate the suspect had been diagnosed with schizophrenia, for which he was previously hospitalized.

In April 2017, he was charged with promoting a detrimental drug in the third-degree and carrying a deadly weapon. The charges stemmed from a case in which police found him in possession of marijuana at Aala Park. When police arrested him, officers discovered a set of “metal knuckles” in his pocket.

The suspect was committed and treated at the Hawaii State Hospital in May 2017 after Judge Paula Devens ruled to suspend case proceedings. Doctors deemed him unfit to proceed because he posed a danger to himself and to others, court records said.

It’s unclear how long he stayed at the state hospital and when he was discharged.