A former Hawaii psychiatric hospital patient indicted Wednesday on a murder charge in the stabbing death of a nurse at the facility had pleaded guilty to a 2020 assault of a state mental health worker, court records show.

A grand jury indicted Tommy Kekoa Carvalho on a second-degree murder charge and a judge ordered him held without bail, the state attorney general’s office said.

Carvalho, 25, is accused of stabbing Justin Bautista, 29, a nurse working at a transitional group home at the Hawaii State Hospital in Kaneohe, a Honolulu suburb.

There were no details available on what prompted Monday’s incident and what was used in the stabbing. Hospital Administrator Dr. Kenneth Luke called it an “unanticipated and unprovoked incident.”

Carvalho pleaded guilty last year to assaulting an employee “at a state-operated or -contracted mental health facility” in May 2020.

According to the Hawaii Department of Health, Carvalho was discharged from the hospital in August and was participating in a community transition program.

That made him no longer a hospital patient, even though he was still on the campus, Luke said Tuesday.

Carvalho was allowed to leave the site briefly during the day, which he had done Monday before the stabbing, Luke said.

In response to questions about whether there were any concerns about Carvalho in light of the 2020 assault, the department said that information would have been considered when the decision was made to discharge him.

“It is public record that the patient pled guilty to assault in the third degree that was reported to have occurred on May 29, 2020, during a State Hospital admission,” department spokesperson Claudette Springer said in an email Wednesday.

She added that such information, along with the patient’s hospitalization record, are “carefully reviewed and considered” when making a clinical assessment over whether to discharge a patient.

The hospital primarily houses patients with significant mental health issues who have committed crimes and have subsequently been ordered there by the courts. Courts may also order people to stay at the facility while they wait to be evaluated for their mental fitness to stand trial.

Carvalho was committed to the state hospital after he was acquitted by reason of mental disease, disorder or defect in a 2016 terroristic threatening case on Kauai, where he’s from.

State Public Defender James Tabe said Wednesday that his office is expected to represent Carvalho at his initial appearance on the murder charge. Tabe declined to comment on the case. Carvalho is scheduled to be arraigned Monday.

Attorney Benjamin Ignacio represented Carvalho in the 2020 assault case. “Tommy was a mental health defendant and that always presents very difficult problems for both prosecuting and defending ... so it’s very unfortunate,” he said Wednesday. “Mental health is a very difficult kind of legal problem.”

The facility has been under scrutiny in the past, including in 2017 when Randall Saito, who spent decades in the hospital for killing a woman, walked off the campus, called a taxi, and boarded a chartered flight to Maui. He then took a commercial flight to California and was arrested in Stockton three days after his escape.

A 2021 lawsuit in federal court says a case of mistaken identity led to a man being locked up in the hospital for more than two years.

Luke said the stabbing has prompted a safety review.