Mental and physical harassment

Hello, my sister started her married live in 2014 December. In U.S. But her husband is unpredictable. What he does and why, it's really not predictable. Sometimes he suddenly stops the car and asks her to get down the car in the middle of no ware. He breaks all the things in the house like T.V and other things. He locks her in the house. Or else he goes out with the keys and my sister waits for hrs outside the door for him to come. He beats her for no reason. Father in law has influenced him a lot. When she says his father in law that he's beating , he doesn't even listen her he simply says her to do her job as a wife. In his and his sons opinion, she just a servent. Or not even that. And now he has sent her back to India and they are planning to divourse. My sister doesn't even know to take help from police. V got to know all these from her friend. Otherwise we will never now. She's so depressed. He harassed her badly. Both physically and mentally. He should be punished for spooling a girls life. Can anyone help us...