The medical examiner reports that Hawaii crime boss Michael Miske passed away from a drug overdose while in federal custody

HONOLULU — A Hawaii crime boss who died in federal detention this month was killed by an opioid overdose, Honolulu’s medical examiner said Tuesday.

Michael Miske, aged 50, passed away due to a combination of fentanyl and para-fluorofentanyl toxicity, as confirmed by the medical examiner’s office. Although the incident seems unintentional, authorities are still looking into the matter, with an autopsy report expected to be ready in approximately 30 days.

It is currently unknown how Miske came into possession of fentanyl and para-fluorofentanyl while being held at the Honolulu Federal Detention Center. Para-fluorofentanyl is an artificially made opioid found in illegal drugs and is known to be more potent than fentanyl.

The Bureau of Prisons did not immediately respond to an email seeking comment.

Miske was found unresponsive at the lockup on Dec. 1. Efforts by staff and emergency medical responders failed to save him, the agency said.

Earlier in July, Miske was found guilty on multiple charges, which included conspiracy to commit organized crime, participating in a murder linked to criminal activities, and involvement in a fatal kidnapping. He was accused of masterminding various illegal acts, such as the abduction of a 72-year-old accountant in debt, releasing a harmful substance in rival nightclubs, and being connected to the death of his deceased son’s close friend.

The conviction entitled the government to take control of up to $28 million in Miske’s assets, including boats, houses and artwork.

He was scheduled to be sentenced on Jan. 30.

The Bureau of Prisons operates 122 federal lockups across the country. It has suffered a series of incidents and crises in recent years, from rampant sexual abuse and other criminal misconduct by staff to chronic understaffing, escapes and high-profile deaths.

In August an inmate and two other people were charged with conspiring to mail drugs to a penitentiary in California, where a mailroom supervisor died after opening a letter that prosecutors said was laced with fentanyl and other substances.