Roommates one asks police to arrest the other who goes?

[Colleen F.]

Three roommates, students, dispute happens, police called, the word I get  is that they attacked each other but only one gets arrested because the other is pressing charges against her. Would you kick out one, the other, or all? Don't know if there is any protective order.   I told them you have a lease, this is not ok,  give me your plan to settle the dispute (e.g. someone moves out/is replaced or ???). I am just looking for experiences.  I don't generally mediate these things between tenants  but my student tenants haven't had this issue before. I don't yet have tenant responses at this point.