An inmate from Rikers Island who was accused of killing an elderly woman on the Upper West Side in 2023 passed away on Monday at the Manhattan Criminal Courthouse. The inmate experienced a seizure while in a holding cell, officials reported.

Terrence Moore, 55, suffered the medical episode and was later pronounced dead around 5 p.m. despite lifesaving efforts — making him the second detainee to die in city custody this year, the Department of Correction said Tuesday.

He was at the courthouse for a scheduled hearing that was ultimately waived until next month, his lawyer said in an interview.

Moore and another suspect were arrested in January 2023 in the chilling murder of Maria Hernandez, 74, inside her West 83rd Street home where her badly beaten body was found by her sister, police said at the time.

He was facing murder and burglary charges before he died.

Moore served a stint of 27 years in state prison after he was convicted of second-degree murder and other charges in another case. He was placed on lifetime parole following his release in 2017, according to records.

His lawyer, Glenn Hardy, said his client didn’t tell him about any health issues during the two years he represented him.

He also denied he was involved in Hernandez’s slaying, Hardy said.

“He had been a gentleman throughout, never any issue, always polite, respectful and he maintained his innocence,” the attorney said.

Moore was detained at the North Infirmary Command, which houses inmates on Rikers who have medical conditions or a disability, though it also holds men from the general population.

Moore traveled to court Monday for the results of a mental evaluation, but that was later delayed until March 28 because Hardy is in the middle of another trial.

“Our deepest sympathies are with the loved ones of Mr. Moore,” DOC Commissioner Lynelle Maginley-Liddle said in a statement.

“We will fully investigate this tragic event to determine the circumstances surrounding his death.”

Attempts to reach the family of Hernandez were unsuccessful Tuesday evening.

Her sister Maria Terrero had remembered her slain sibling as “very kind, loving and caring.”

“She never ever ever had [any problems with anyone]” she said in 2023. “I think the person was looking for somebody else.”

Last Wednesday, Ramel Powell, 38, became the first person to die in a city jail this year. More details about his death were not provided.

The correction department has faced ongoing criticism for the horrid conditions at the jail complex on Rikers Island which could lead to a federal takeover.