Mental Harrasment

This is a case of my brother, he is married since more than 1.5 yr and recently blessed with son. This is his first marriage and his wife is second marriage. His wife has very bad temper, always fights without reason, abuses, abuses in laws, sometime taken hands too on them, they were living separated but due to pregnancy they are now living with parents (in laws), the marriage was never happy since its start somehow with the interference of parents and family it was pushed on hope one day in will get better. Issues were raised to his in-laws but they say manage it yourselves she like this and behaved same to her previous husband. she always threatens everyone to implicate on false case.The intimation has been already obtained from local police on the treats, abuse and harassment done by her. My parents are not willing to stay with her, she is not ready to leave the house and move to rented place. Due to abusive, manipulative nature, she sometimes ask for compensation for her and kid but doesnt stick to her word.She is aware of law and repercussion. More facts:- They are both are working in reputed firm. My brother has recordings of all conversation and threats. It is love marriage, all marriage expense was born by my brother as my parents were against this match. My brother 2 yr younger to her. After staying is when realized the actual reason why first husband divorced her, it was on MC but case of filed by his previous husband. We have the record of Divorce papers. She was on depression during pregnancy and have confirmed doctors prescription. My brother is totally in hell, his parents security is in stake, office work pressure is so high doesnt have idea what to do. But he doesn't want to live with her anymore. Pls help and suggest.