ATLANTA – Georgia's public safety chief says he's stepping down just weeks after an entire graduating class of the State Patrol's Trooper School was fired or resigned after being accused of cheating on an online exam.

Department of Public Safety Commissioner Col. Mark McDonough announced his resignation Thursday after Gov. Brian Kemp told the commissioner he wanted new leadership.

Kemp thanked McDonough in a statement for ``his dedicated service, leadership, and sacrifice. We wish him the very best in the years ahead.''

McDonough said in late January that 30 troopers were fired after being accused of cheating on an online exam for the speed detection operator component of the school’s curriculum. One trooper resigned after the cheating allegations came to light. All were August graduates of the 106th Trooper School.

The investigation began in October after officials learned about the allegations from the girlfriend of one of the cadets, who said she took the online test for him.

McDonough said then that all the graduates signed an oath to uphold professional conduct and standards, which they violated, leading to their dismissals.