You don't state if there is a mother involved. You are not protecting your brother if your father has become this violent. From past experience I can only tell you that it gets worse never better. Yes you can sue in a civil suit, but I recommend filing a criminal complaint. As for your brother, the state authorities will have to deal with the issue. I doubt you will be given custody of him, but that is dependent on many other factors.
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Mr. Sarno is licensed to practice law in NJ and NY. His response here is not legal advice and does not create an attorney/ client relationship. The response is in the form of legal education and is intended to provide general information about the matter in question. Many times the questioner may leave out details which would make the reply unsuitable. Mr. Sarno strongly advises the questioner to confer with an attorney in their own state to acquire more information about this issue.
I agree with both of my collegues. Physical assault and emotional abuse are much more urgent matters to addrerss then whether you can file a lawsuit. Get advice from an abuser or domestic violence counselor as suggested by my collegue, this will assist you in dealing with the abuse you have suffered. The simple act of you filing a criminal complaint under the Domestic Violence Act can have very strong impacts on the abuser. Any such complaint will likely result in a least short -term incarceration for the abuser, the issuance of a restraining order on the abuser, and mandatory anger management couseling for the abuser. Get the counseling (perhaps your brother needs it too). Lastly, I agree with my collegues that you cannot dictate what you are going to do to protect yourself, by concerns as to whether the Court will award you custody of your brother. Good luck.
This response does not constitute legal advice. It does not create an attorney-client relationship. This answer is provided solely for informational purposes, for you to use as a starting point when speaking directly with a lawyer. I urge you to immediately contact an experienced criminal defense lawyer admitted to practice law in NJ before you make any decisions about this case.