I have a relative who's K1 visa was approved by USCIS but when she was interviewed by the consul representative she was ask to submit a Marriage Index (Certificate of no Marriage). She got one in our country but the Sponsor who is in San Diego Ca. don't know where to get this document or if it's even available here in US. Both of their spouses are dead and they have Death Certificate to prove that. My question is where to get this document and if it's not avaiable , what other documents can they present?