At least three of the officers involved in the fatal beating of Robert Brooks, a New York man held at the Marcy Correctional Facility in upstate New York, were previously accused of assault, according to court documents obtained by CNN.

The state prison inmate died Dec. 10 after being beaten by correction officers at Marcy Correctional Facility in Oneida County.

Thirteen state department of corrections employees have been suspended without pay while one correction officer resigned after the deadly attack