Question about domestic abuse charges?

Alright so my mother and her boyfriend got into a fight one night, at one point he choked her and he bit her (yes bit her lol, my mom gave him a black eye and fat lip). So a week ago he got arrested for it, and now he's got charges for strangulation and 2 misdemeanors. They love each other again (yeah I know shes retarded). Anyways he has court tomorrow, if my mom goes can she like drop the charges or is it in the governments hands now?