If a USCIS denial has just occurred or looks likely, one of the best things to do in preparation for possible litigation is to request from USCIS your Alien File or A-File pursuant to the Freedom of Information Act (FOIA). The A-File is supposed to contain all of the documents USCIS maintains on the person in question.
Having these documents in hand is important because most denial cases against USCIS are filed under the Administrative Procedures Act (APA). APA cases are decided on the “administrative record.” No new evidence is typically permitted to be introduced by the immigrant or the Government in an APA case. Therefore, knowing the full scope of what was already submitted to the Government and what documents they used to adjudicate your case is critical. The best source to get as complete a picture as possible before starting a lawsuit is the A-file.
Below is a link to make a FOIA request to USCIS. If you do make a request, make sure to keep detailed records of the request in case USCIS does not completely or promptly respond to the FOIA request.