22 CFR §51.23

1. (a)The applicant has the burden of establishing his or her identity.
2. (b)The applicant must establish his or her identity by the submission of a previous passport, other state, local, or federal government officially issued identification with photograph, or other identifying evidence which may include an affidavit of an identifying witness.
3. (c)The Department may require such additional evidence of identity as it deems necessary.