CRANSTON — An Adult Correctional Institutions officer has been arrested on simple assault for allegedly striking a handcuffed inmate in the face.

The correctional officer, identified as Mark Denis, 55, of Rehoboth, Massachusetts, was arrested Tuesday following a joint investigation by detectives from the Rhode Island State Police Major Crimes Unit and the Rhode Island Department of Corrections’ Office of Internal Affairs.



The investigation found that Denis allegedly struck an inmate in the face with his hand. The inmate, who is assigned to the maximum security unit, was handcuffed while awaiting a disciplinary proceeding at the prison at the time. The victim was not seriously injured and did not require medical treatment.



Denis surrendered at state police headquarters in Scituate on Tuesday night. He was processed and arraigned before a bail commissioner, and released on $1,000 personal recognizance, pending further court action.



The charge of simple assault or battery is a misdemeanor, punishable by up to one year in prison and/or a fine up to $1,000.



Denis has been on paid administrative leave since January.

Denis is the second corrections officer arrested this month. State police investigators arrested a corrections officer on May 14 and charged him with having sex with three female prisoners over a one-year period.



Collins Umoh, 40, of 24 Clayton Rd., Warwick, was charged with seven felony counts of having sexual relations with inmates. Police say between July 2017 and August 2018 he had sex with three women housed in the Gloria McDonald Correctional Facility at the Adult Correctional Institutions, in Cranston.



Umoh, a corrections officer for 11 years, was released on $20,000 personal recognizance and has been on paid administrative leave since August.