HONOLULU (AP) — A former Hawaii prison guard was sentenced to 12 years in prison for assaulting an inmate.

Jonathan Taum supervised three other guards while transporting an inmate at the Hawaii Community Correctional Center in 2015. According to U.S. prosecutors, the inmate became frightened and the correctional officers took the inmate to the ground and punched and kicked him repeatedly.

“As the other officers beat the inmate, Taum verbally encouraged them to continue,” the U.S. attorney's office in Hawaii said in a statement Friday.

A federal judge sentenced Taum, 50, Wednesday to three concurrent prison terms, the longest being 12 years, according to prosecutors.

The inmate's jaw, nose and orbital socket were broken during the Big Island assault, prosecutors said.

Taum led a multi-year cover-up of the abuse, prosecutors said.

Taum and two former guards were convicted of civil rights violations for the assault. A fourth former correctional officer pleaded guilty for his role in the assault and cover-up.

The Hawaii Department of Public Safety fired the men in 2016.