The most brutal scenes are of domestic violence. An angry husband beats his wife throughout the movie, and we can see her bruises. One of the reasons this movie is rated R.
The son, angry at his father, talks about hurting his father, twice, one involve killing him and another about "break his jaw."
A robbery takes place, and the man being robbed has a gun to his head.
We see a man threatening a guy for not getting his stolen money back.
The same husband grabs his son at the end, in anger. We see threats of an "ass-kicking" earlier on.