Body-worn camera footage released Friday shows correctional officers at the Marcy Correctional Facility in upstate New York punching and kicking a handcuffed inmate in a fatal beating that is now under investigation by the New York attorney general.

Robert Brooks was pronounced dead on December 10 at Wynn Hospital in Utica, according to Attorney General Letitia James. Brooks, 43, had been serving a 12-year prison sentence since 2017 for first-degree assault, prison documents show.

CNN has reviewed the footage, parts of which show surrounding officers kicking and punching Brooks, who has his hands handcuffed behind his back in a medical examination room. Brooks’ face appears bloody in some of the footage.

At one point, an officer appears to shove something in Brooks’ mouth before repeatedly hitting him in the face. Another officer then punches Brooks in the groin before using a shoe to strike him.