A man at Limestone Correctional Facility was killed Wednesday in an apparent inmate-on-inmate assault, the state prison system confirmed.

The Alabama Department of Corrections said Ariene Kimbrough, 35, was discovered deceased inside his cell at the north Alabama prison. The prison system did not say how Kimbrough died. The agency said the death is under investigation.

The state prison system has come under criticism and federal scrutiny for high rates of violence.

The U.S. Department of Justice has an ongoing lawsuit against Alabama, arguing that the conditions in state lockups are so poor that they violate the U.S. Constitution. The state has acknowledged problems within state prisons but disputes the Justice Department’s accusation.

The prison system reported in monthly statistics that at least 11 prisoners were killed by other inmates in the fiscal year that ended in September. However, the prison system said the reported number does not include deaths that are still under investigation.

The Equal Justice Initiative has reported that at least 18 inmates died by homicide in 2022.

The Alabama Department of Corrections reported that 225 inmates died in the last fiscal year. At least four of those died by suicide, according to statistical reports.