If an investor wants to use funds for an EB-5 investment, the source of those funds will be required by USCIS. Without direct, primary evidence, an investor may be able to demonstrate lawful source of funds through secondary evidence and a totality of the circumstances. A sworn affidavit explaining where the funds originated may be suitable in certain circumstances. Because lawful source of funds is a key requirement of the EB-5 Program, it is important to retain an experienced EB-5 immigration attorney to help compile the necessary documentation.