Joseph Tui Jr., the man accused of beating an inmate to death, appeared in a Honolulu courtroom Tuesday morning and admitted to the judge that he sexually assaulted an inmate.

"I also sexually assaulted an inmate," said Tui.  "I'm not homosexual.  I'm not gay.  I just wnat to say I sexually assaulted an inmate in numerous ways I don't know why they never put them on the charges."

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Tui, 32, was charged with first-degree murder in the beating death of 76-year-old Cyrl Chung at the Oahu Community Correctional Center on Saturday.

Tui was serving time at OCCC for a misdemeanor assault charge.  He was in the holding unit for threatening OCCC staff.

Chung was awaiting trial on robbery charges.

According to court documents, while being treated for injuries sustained in the alleged assault, Tui admitted "he was punching and kicking the male in his head."

"Mr. Tui has a history of severe mental illness," said attorney Myles Breiner.

Breiner says Tui should have been in protective custody or in isolation and the decision to place him with the general population was "a great error."

"To place Joseph Tui in a cell with another inmate placed Tui at risk and certainly placed that other inmate at risk given his history of mental illness and assaultive behavior," said Breiner.