KANSAS CITY, Mo. (AP) — Four Missouri prison workers were fired after an investigation into the death of an inmate whose family is demanding to know what happened.

Othel Moore died Dec. 8 at the Jefferson City Correctional Center after a cellphone search, Missouri Department of Corrections spokesperson Karen Pojmann said in an email Friday.

She said a cause of death hasn’t been determined. She declined to release additional details about the terminations, saying that the Cole County Sheriff’s Department is investigating. The Associated Press left messages for the county sheriff, prosecutor and medical examiner seeking comment.

The family’s attorney, Andrew M. Stroth, said Moore, a 38-year old Black man, was pepper-sprayed, strapped in a restraint device and had blood coming out of his ears and nose. He blamed members of the prison’s Corrections Emergency Response Team, which handles disturbances and emergency situations. Stroth said several inmates heard Moore screaming that he couldn’t breathe and alleged that he was left to die.

No litigation has been filed, but Stroth alleged that Moore’s death was part of a broader problem.

“The Missouri prison system has a pattern and practice of abusing Black inmates,” he said. “So it’s a big civil rights issue. And Othel Moore is just one of the most egregious cases.”

He said the family is calling for authorities to provide video, investigative reports and the names of the terminated officers.

Pojmann declined to release the names of the workers, who were terminated Feb. 22, saying that individually identifiable personnel records are closed to the public.

Moore, who grew up in St. Louis, was serving a 30-year sentence for second-degree domestic assault, first-degree robbery, armed criminal action, possession of a controlled substance and violence to an inmate or employee of Corrections Department, Pojmann said.