My question involves criminal law for the state of: Michigan
My little sister was attacked last night by her new boyfriend. He was drunk and accused her of flirting with another guy. He beat up the guy, and then attacked my sister. He is a trained MMA fighter and she is very small. He beat her face pretty badly - one side is a mess. He also took her phone from her so she couldn't call for help, and kept her inside her vehicle for 6 hours. He took her ATM card from her purse and would hit her every time she refused to give him her pin number. She finally gave in and told him the pin, and at that point, he left, went to an ATM and withdrew $500. She drove off at that point and went to our parents for help. Our dad took her to the police department to press charges, and the cop on duty told her it likely wasn't enough for charges to be filed.
I don't understand. He assaulted her repeatedly, even choked her to the point of passing out once. He basically extorted her pin number out of her by hitting her every time she refused to give it. He held her against her will for hours and withheld access to her phone - isn't that kidnapping? And then to top it off, he used her card to steal money from her bank account.
Why wouldn't this be enough for the county prosecutor to go after him? What can we do?

