You have no authority to do so. Charging decisions rest 100% with the DA.
Talk to his lawyer NOW, and do NOT discuss the case with anyone else. DA's will "sometimes" drop a first complaint if the victim wants them to, but not usually. Your boyfriends lawyer will know the best way to go about it.
If he gets a felony OR misdemeanor DV conviction, or even a diversion or ACD in which he 'admits culpability', then the Federal "Lautenberg Amendment" means he is barred for life from owning or possessing a firearm. This *includes* access to guns on military service, so if he is still in the service - active or Guard / Reserve - he is OUT with an OTH discharge - that means no VA benefits, no GI Bill college help, *nothing*.
Speak to HIS lawyer... NOT to the DA.