The only person in Hawaii acquitted of murder by reason of insanity due to methamphetamine abuse is no longer under State Hospital or court supervision.

Leonard Kuhia, 52, walked out of state court a free man last month after a state judge discharged him from probationlike supervision.

In 1993 Kuhia killed his sister’s boyfriend with a shotgun. State law does not excuse criminal behavior committed while under the influence of drugs or alcohol. But the judge who acquitted Kuhia said the law does not rule out the insanity defense when a defendant develops a mental illness from drug abuse.

The state did not appeal Kuhia’s 1994 acquittal.

However, based on a later Hawaii Supreme Court decision in another case, no other defendant has been or is likely to be acquitted by reason of insanity because of drug or alcohol abuse.

After his acquittal, Kuhia was committed to the Hawaii State Hospital. He was discharged in 2002 and ordered to live in a clean-and-sober facility and to abide by probationlike conditions under court supervision.

Just two months earlier the court had granted Kuhia’s request to attend spring semester classes in the University of Hawaii’s College of Engineering. He had already been taking classes at Windward Community College.

By 2008 Kuhia completed a residential drug treatment program, was no longer required to live in a monitoring facility and received his bachelor’s degree in mechanical engineering. By 2011 he was living with his wife and child and employed as an engineer.

Kuhia declined the Honolulu Star-Advertiser’s request for comment.

He never denied that he killed 29-year-old Danilo Agbayani on Jan. 4, 1993, in the driveway of Agbayani’s Kunia Camp home. He said voices in his head told him to do it.

A mental health expert hired by the defense and two of three court-appointed experts said Kuhia developed paranoid schizophrenia or a delusional disorder from years of methamphetamine abuse. They all said Kuhia was suffering from the mental illness when he shot Agbayani and that the mental illness impaired his ability to distinguish right from wrong or to follow the law.

The third court-appointed expert agreed that Kuhia’s ability to know right from wrong or to follow the law was impaired when he shot Agbayani. But he said the impairment was not due to mental illness.

He said long-term use of methamphetamine affected Kuhia’s brain in such a way as to produce a condition that resembles paranoid schizophrenia.

Kuhia had told at least one of his examiners that he was not under the influence of methamphetamine at the time of the shooting because the last time he smoked the drug was two weeks before.

Circuit Judge Michael Town acquitted Kuhia of murder because he said Kuhia had met his burden to prove that he was not legally responsible for his actions when he shot and killed Agbayani.

In his written decision, Town said the case “presents the question whether drug-induced or exacerbated mental illness can ever justify a defense to a criminal charge,” adding, “The short answer is yes, under current Hawaii law.”

Since the state did not challenge the acquittal, Hawaii’s appeals courts did not get the opportunity to review the decision.

The Hawaii Supreme Court, however, referred to Kuhia’s case in a 1996 decision on an appeal by a defendant in another case and interpreted the acquittal as an application of an exception to the intoxication law.

The exception allows the use of self-induced intoxication as a defense if the intoxication is greater than what is expected, based on the amount of drug or alcohol consumed, and the person has, but doesn’t know he has, a condition that makes him susceptible.

The Supreme Court concluded that the exception was the reason for Kuhia’s acquittal even though Town made no mention of it and there was no evidence presented in trial of the amount of methamphetamine Kuhia consumed. There was also no evidence presented of a mental or physical examination to determine whether Kuhia had a pre-existing condition that made him susceptible to the drug.

In a 2000 decision on an appeal by another murder defendant, the Supreme Court said, without mentioning the Kuhia case, that the reason Town stated for acquitting Kuhia cannot be used as a defense under Hawaii law:

“We decline to adopt (the) argument that a drug-induced mental illness is a defense because to do so would be contrary to the legislative intent underlying” Hawaii’s intoxication and insanity defense laws.

Even before the 2000 Supreme Court decision, defendants rarely attempted the insanity defense due to substance abuse “because it’s so difficult to prove,” state Public Defender Jack Tonaki said.

He said defendants who have mental illnesses often self-medicate with alcohol or illegal drugs and that “99 percent of the time there is heavy, voluntary drug use immediately before the crime is committed.”