Deal issued an executive order Monday that suspends Mann for a shorter period than the 60-day maximum allowed under state law.
The 40-day suspension was recommended by an investigatory committee made up of two sheriffs and Attorney General Chris Carr.
Mann has pleaded not guilty to charges of indecency and obstruction after an Atlanta police officer arrested him near Piedmont Park on May 6. His trial is scheduled for July 7 in Atlanta Municipal Court.
Mann tried to stop Deal’s investigation, but a Fulton County judge allowed it to continue last month.
Mann also pre-emptively suspended himself for a week for violating the code of conduct of the DeKalb Sheriff’s Office. Mann wrote in a memo to employees that he wasn’t admitting guilt, but he said he deserved to be disciplined for bringing criticism to the county.