The DA's not.
True, but no DA can press charges if he doesn't have adequate information from the police with regards to what happened. If the cops didn't arrest anyone, make any reports, take down notes, etc. then there's nothing for the DA to work with.
Unions will always protect their own. That's why nearly all unions can get away with committing as many acts of violence as they damn well please. They know the cops have their backs.
In Columbus, he might as well be. Although there is an "R" after his name, Franklin County Prosecutor Ron O'Brien has his head firmly up the backside of the Democrat Mayor and all Democrat City Council of Columbus.