My sister husband torture

My sister married in 2012,from the day of marriage till 3months he was take caring of my sister in better way but after 3months for some or other thing he is shouting on my sister. Most of the times simply shouting or taking some silly topics and shout with her. Torturing always and blaming her more and more. Even his mother in law supporting son only. This issue is going on years to years but now he is not taking care sister, daughter and son. He is not spending for any basic needs, very calculative and even he did not send to school his daughter. He became more selfish, egoism. Always looking his wife and children as slaves like below his leg,beating his wife some times Kindly suggest any remedy or suggest to recover there life.