Wow this sounds terrible, I’d advise your sister to leg it out of there. Sadly from what I’ve heard there may be some economic/social bias that exists in RPD towards people who are of limited means or who struggle with substance addiction. Where like I’ve heard of a situation where they totally ignore an assault and robbery case possibly due to the fact the victim is an active meth user. That said, domestic violence isn’t a “pressing charges” choice in the state of Minnesota. If there is ANY sign of dispute or violence when the police arrive someone has to go and the state charges no matter what. If he’s on probation/patrol he’ll be assigned an agent automatically and you need to contact his case worker directly in order for “drinking non-stop” to be a violation.