Idaho court case asks: Can you be guilty of aggravated battery if you’re delusional?

Ruben Diaz, the suspect accused of attacking a Boise man last year, appeared in court Thursday while attorneys argued for two hours about whether his constitutional rights had been violated and what his state of mind was at the time of the attack.

Diaz, 36, was charged with aggravated battery, an enhancement for the use of a deadly weapon and resisting arrest after he attacked a 76-year-old stranger, Gary Vinsonhaler, in November 2018. Vinsonhaler was outside his Southeast Boise home doing yard work; at the time, Diaz lived in an assisted living home nearby.

Ada County District Judge Jonathan Medema will issue a written opinion on whether his constitutional rights were violated and whether the state can appeal an earlier decision.

Diaz was temporarily deemed unfit for trial due to mental illness, but his competency has since been restored, following hospitalization, and he is preparing for trial next year. Diaz has a lengthy history of mental illness, according to a previous Idaho Statesman investigation, and a history of acting violently when not correctly medicated.

At the time of the stabbing last year, Diaz was living at the Hancock House, a state-licensed assisted living facility, designed to help people with serious mental illness. It is located only a few blocks away from the stabbing victim’s home.

Psychologist: Diaz thought victim was an alien

Prosecutors on Thursday pushed for the judge’s permission to appeal the district court’s earlier decision to allow James Davidson, a licensed psychologist, to testify at Diaz’s trial.

Davidson was retained by the defense to consult on Diaz’s case. He wrote a report to the court in September that said Diaz “was suffering a delusion and believed he was attacking an alien when he committed the instant aggravated battery,” according to a copy of the prosecutor’s motion.

Deputy Prosecutor Whitney Welsh argued that it isn’t relevant whether Diaz was delusional at the time — only that he did attack a person.

Diaz’s defense attorneys argue that his delusions are very relevant.

Idaho is one of just four states — with Kansas, Montana and Utah — that do not allow an insanity defense.

The U.S. Supreme Court is currently considering whether states overstepped their constitutional authority by abolishing the insanity defense. (The high court in 2012 declined to hear an Idaho case that made similar arguments.)

Diaz’s attorneys are not arguing insanity, but just that his delusion should be factored in by jurors.

His attorneys argued Thursday that in order to be guilty of aggravated battery, a defendant has to knowingly attack a person — “a living human being.” Diaz didn’t know he was doing that; he thought he was attacking an alien, his lawyer told the court.

Prosecutors said they’re concerned that the state may be forced to prove Diaz knew the person he was attacking was “a human being” rather than an alien.

Defense attorney Kyle Schou wrote in court filings that “If a jury believes Dr. Davidson’s testimony that Mr. Diaz believed Mr. Vinsonhaler was an alien, then the State would not meet its burden of showing that a person was the object of Mr. Diaz’s intent.”

Judge considers whether Diaz’s rights were violated

Diaz’s defense attorneys also argue, in a separate court filing, that prosecutors violated their client’s right to attorney-client privilege. They contend prosecutors requested a copy of the jail’s video recordings of a meeting between Diaz, his defense attorneys and Davidson, the psychologist.

Because Diaz’s attorneys, Schou and Kate Enterkine, were present and Davidson may testify at trial, they argue that Diaz’s rights to due process were violated.

According to the defense’s motion, Davidson always met with Diaz at the jail when his attorneys were present. Prosecutors asked through a discovery request on Sept. 17 for copies of any recordings of Diaz’s meetings with Davidson. On Sept. 19, prosecutors separately emailed an Ada County sheriff’s deputy requesting the same videos and obtained copies that way.

On Thursday, Ada County Deputy Prosecutor Kendal McDevitt said he has not viewed the video yet, but noted that it does not include audio of any conversations. He argued that it was not a violation of Diaz’s right to attorney-client privilege because prosecutors were only seeking parts of the interaction with Davidson that related to medical or scientific reports.

Enterkine argued that even without the audio, the video can show Diaz’s lips moving and some of the paperwork exchanged between the people in the room.

The defense asked the judge to remedy the invasion of attorney-client privilege by dismissing the charges, or by ordering that the Ada County Prosecuting Attorney’s Office recuse themselves from the case and appoint a special prosecutor.

Medema said Thursday that he would review the video himself before making a decision on if it invaded attorney-client privilege.

Medema did not say how quickly he would issue his written opinions, but Diaz remains in custody at the Ada County Jail without bond while he awaits trial.

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Reporter Ruth Brown covers the criminal justice and correctional systems in Idaho. She focuses on breaking news, public safety and social justice. Prior to coming to the Idaho Statesman, she was a reporter at the Idaho Press-Tribune, the Bakersfield Californian and the Idaho Falls Post Register.