Saturday | December 10, 2016
About Us | Contact | Subscribe

Homicide suspect’s mental state explored


Tribune-Herald staff writer

Two psychiatrists said Friday that Sean Ivan Matsumoto suffers from psychotic episodes and paranoid delusions, but each reached a different conclusion on whether the double-homicide suspect is fit to stand trial.

Dr. Henry Yang testified in Hilo Circuit Court that Matsumoto, who’s accused of the Feb. 11 shotgun slaying of his 45-year-old girlfriend, Rhonda Lynn Alohalani Ahu, and her 74-year-old mother, Elaine Ahu, in their home in Hilo’s Waiakea Houselots neighborhood, that Matsumoto suffers from long-term mental illness that would prevent him from competently assisting with his own defense.

Another psychiatrist, Dr. Andrew Bisset, told the court that Matsumoto “is somewhat impaired by his paranoia toward the world” but “has an adequate understanding of the proceedings, of the charges against him, legal processes and so on.”

Yang, who found Matsumoto unfit to proceed, said the 34-year-old suffers from “substance-induced psychotic disorder secondary to amphetamine abuse.” He said that Matsumoto has “a long history of psychiatric and psychological treatment, and also a long history of substance abuse.”

He noted that Matsumoto had been prescribed Seroquel, an anti-psychotic drug, Lexapro, a drug used to treat depression and general anxiety disorder, and Xanax, which is used to treat anxiety and panic disorder, but had not been prescribed those drugs since being jailed in February at Hawaii Community Correctional Center.

“When I interviewed him, I believe he was suffering from persecutory or paranoid delusions of individuals wanting to hurt him, individuals in jail who could hear what he was thinking about, and thoughts that his life was being played out over television. This is consistent with symptoms that I had reviewed in his medical file,” Yang testified.

Yang said he felt Matsumoto’s psychosis and paranoia would be detrimental to his efforts to assist defense counsel at trial.

“If he is in court feeling as though the jury or observers are hearing what he’s thinking about, or hearing voices commenting on his behavior or commanding him what to say or do things that no one else would know, I think it’s highly likely that would affect his ability to assist in his defense to his fullest ability,” he said. “Here’s an individual that was on medications before he went to jail. Although he admitted to me that he was not cooperative in taking the medications, he has a history of being on these medications and, in fact, wanted the medications when I interviewed him in jail.”

Yang estimated that “25 to 30 percent” of HCCC inmates are prescribed psychotropic medications. He also said that Matsumoto’s long-term amphetamine abuse still affects his mental state, even though he has purportedly not taken the drug while incarcerated.

“The drug causes brain damage, and scientists don’t really understand the exact biochemical mechanism by which it does that, but it’s well-documented in the literature that chronic substance abuse of amphetamines can cause a chronic schizophrenia-like syndrome in about five to 10 percent of individuals who use it on a chronic basis — chronic being defined as a year or more,” he said.

Bisset, who found Matsumoto fit to proceed, diagnosed him with schizoaffective disorder, which he described as “a combination of a cycling mood disturbance as well as psychotic symptoms.”

He defined “cycling mood disturbance” as “a mood disturbance that goes up and down, periods of depression, periods of increased energy and agitation, sometimes to the point of mania, but not in the case here.”

“His paranoia was generalized. He didn’t trust anyone; nobody cared. He said his public defender didn’t care. They all work together; everyone is against me,” Bisset said, adding that Matsumoto “indicated the possibility that he might lose control (in the courtroom), lose his composure were his exact words.”

Neither physician thought Matsumoto was malingering, which both described as faking symptoms to gain something.

“I would not say that he is malingering,” Bisset said. “What I would say is he has established diagnoses, including schizoaffective, which we talked about, as well as anxiety disorder and panic attacks. However, his presentation during the course of the interview appeared an exaggeration of symptomology to further his quote-unquote mental health events.”

Matsumoto, who is being held without bail at HCCC, sat quietly at the defense table during the proceedings. Judge Greg Nakamura continued the hearing to Oct. 28 at 8:30 a.m. to allow testimony by the third mental health professional who examined Matsumoto, psychologist Dr. Thomas Cunningham, who found him fit to proceed.

The judge will rule on Matsumoto’s fitness after all testimony is heard.

Email John Burnett at


Rules for posting comments