In a case that prosecutors said involved “a strong component” of mental illness, Mbyayenge Mafuta pleaded guilty Thursday morning to charges of involuntary manslaughter and aggravated assault in the death of his cellmate at the Northwest State Correctional Center in almost two years ago.

During a brief hearing in Franklin County Criminal Court, State’s Attorney Bram Kranichfeld told Judge Alison Arms that the family of the victim, Jeffery Hall, “fully supported” the plea deal that was reached. The deal will see Mafuta, 23, serve 15 to 30 years on the two charges, with all but eight years suspended. With credit for time served, Mafuta will spend six more years in prison and will be placed on probation for 25 years when he completes his prison term.

“We recognize that Mr. Mafuta has taken responsibility for his actions,” Kranichfeld told the judge. “Our hope is that Mr. Mafuta will commit to his treatment” following his probation, the prosecutor added, citing a “strong component in this case of mental health and mental illness.”

Seated in court between two of his lawyers, Mafuta said little during the 15-minute hearing other than to answer “yes” to the two guilty pleas and admit he understood the terms of the agreement.

Hall’s family chose not to attend the hearing, Kranichfeld said, although they requested to be present for the sentencing portion of the case, which is expected once a pre-sentence investigation is completed in 45 days.

On December 22, 2022, Mafuta attacked Hallrepeatedly kicking him in the head in the cell the two men shared, according to investigators. Mafuta believed Hall had stolen items from other incarcerated people, court records indicate.

The attack came just three days after Mafuta was returned to the general prison population after he was placed in solitary confinement when he told guards he was “hearing voices and they weren’t going to stop,” according to a police affidavit filed in the case.

At the time, a behavioral health coordinator for VitalCore Health Strategies, the private prison’s medical contractor at the time, reported that a mental health professional “was able to consult with Mr. Mafuta and we think it’s OK to take the measures of caution and room condition.”

The coordinator said it was determined Mafuta had “no current thoughts” of harming himself or others, according to a police affidavit.

Room died in March 2023 from the injuries sustained in the attack, and the forensic doctor afterwards considered his death a homicidewhich led to the introduction of murder charges in the case.

In August, Hall’s estate filed a wrongful death lawsuit against VitalCore, ca first reported in Seven Days. This lawsuit cites several diagnoses of mental illness reported by Mafuta.

Mafuta was detained at the North West center after being charged vandalizing 33 houses in Burlington in August 2022. He was returned to the same facility after his Thursday court appearance.

Alan Keays contributed to this report.