To apply for a U Non-Immigrant status, complete and submit: Form I-918
Form -918 Supplement B, U Non-immigrant Status Certification. The Form has to be signed by and an authorized officer of the certifying law enforcement agency. This can include Federal, State and Local law enforcement agencies; Federal, State, and local prosecutors’ offices Federal, State, and local Judges; Federal, State, and local Family Protective Services; Equal Employment Opportunity Commission; Federal and State Departments of Labor; and other investigative agencies. The certifying agent must state that you were helpful. They must state that you are currently being helpful, or will likely be helpful in the investigation or prosecution of the case. Without the certification, the applicant will not be eligible for the U Visa.
If any inadmissibility issues are present, you must file a Form I-192 (Application for Advance Permission to Enter as Nonimmigrant). This allows one to request a waiver for the inadmissibility
A personal statement describing the criminal activity of which you were a victim.