Is he/she a US citizen? Try to find the US citizen abuser's birth certificate, US passport, naturalization certificate of the I-130 approval notice he/she filed for you. These can all help.
Is the abuser a lawful permanent resident? Try to find a copy of his green card, approval notice fo the I-130 or any documents with his A number. What if you cannot find this? Are there anyone else who may have this information? If still no luck, get notarized declarations from friends, family,employers, coworkers or anyone else who knows of the abuser's status.Often relatives of the abuser will help as long as the abuser does not find out. Assure them that what they write is confidential. You may want/need to gather these documents before you leave the abuser. Be sure they are put in a safe place or given to a trusted person where he does not discover them. Be careful that you do not put yourself in danger.
Prove you lived with the Abuser
Look for copies of leases, utility bills, children's school records, letters to both of you and again if all else fails, notarized statements from those who saw you lived together. What about joint bank accounts, joint memberships, Sam's Club, bills from the furniture store for joint purchases. go back to the stores and vendors and get as much evidence as possible. Look for photographs together. Maybe other people took photos? Christmas cards you sent out together that someone may have kept? Think of places you went together and people who may have records or recollections of those events.
How Do I Show the Abuse?
Do you have police reports, other unrelated court records of the abuser generally, restraining orders, 911 transcripts, medical records (even if you never told the doctor the real reason why you were injured or said that you fell by yourself), domestic violence shelter records, photos of your injuries or property injuries (holes in walls, damage to your belongings), letters of apology from the abuser, school records regarding abuse to children and most important, YOUR STATEMENT.See the last section
Show good Moral Character
Get a police clearance for yourself and get signed statements from other people who know you are of good character such as friends, neighbors, religious leaders. Tell the police it is for your own records.
How do I describe what happened to me?
Your statement is not going to be easy to write as you must revisit painful times. It is often helpful to talk to a trusted friend or mental health counselor or therapist. Writing down what happened is imperative as you will have forgotten some of the behavior of the abuser. Have that trusted therapist help you, but it is your story and you must be the one to dictate it. USCIS could look at a statement that is too polished as not being as truthful.
Include information on every incident of abuse, verbal and physical are both important to relate in your statement. Talk about how you met your spouse. Where did you meet? How long did you date? Do you have children together? How did he treat you during pregnancy? How did he treat your other children? How did he treat pets? When did his behavior change? Was he violent and then apologize? Did he have a drug or alcohol problem? Did you ever call the police, why or why not? Did he hold your immigrant status over you? Did anyone witness the violence? Was there sexual abuse? Were you held captive - not allowed contact with friends or family? Did he monitor your contacts? Did he threaten to hurt your family if you did not cooperate? Did he withdraw food from you? There are are many types of abuse and you need to think about all behavior of the abuser. Best wishes in your application.