<human>: California, east bay area

Background: rooomy friend was in a relationship with an abusive boyfriend for several years and only recently broke up. However, the incident which caused this breakup also ended in her being arrested. Both her and her boyfriend were intoxicated on the night the incident occurred, and had an argument which turned physical. He wanted to leave and she wouldn't let him, believing he would drive drunk. She was beaten badly, whilst he received a large cut on his head from breaking a window. Cops showed up and after brief questioning she was arrested for "kidnapping" and possibly also assault as they believed his head injury was caused by a bottle that she hit him with. In any case, supposedly  the police are pressing charges while the boyfriend is not.

Can you give me the gist of the text in a nutshell?
<bot>: I wish to know if the police can press charges even if the ex bf does not, and what is the likelihood of her being sent back to jail.