In a recent news report relatives of the San Bernardino bombers were found to be in violation of U.S. immigration law.
The report shows that they were in a classic case of a marriage of convenience for immigration purposes.
How does an applicant prove a marriage is genuine anyway?
Well there is sentimental evidence and hard evidence.
A selection of photographs that capture the essence of a relationship, such as spouses together on vacation, with each others close family and at major life events (birthdays, holidays, vacations, etc.) are usually well received by the government. Other sentimental evidence includes copies of birthday/holiday cards, email printouts, Facebook printouts, love letters, wedding invitations and reference letters from close friends or family that confirm the nature of your relationship.
Hard evidence includes copies of a power of attorney, copies of wills or life insurance policies, naming each spouse as the others beneficiary, copies of leases or land title certificates, showing both spouses as tenants or owners and copies of bank statements, showing both spouses as joint account holders. Other such evidence is boarding passes, hotel reservations, receipts for gifts and dinner, and passport stamps to prove that visits between spouses actually took place. Phone bills are an excellent way to confirm communication between spouses while separated.
Obviously these parties knew how to tell a story and use some of this kind of evidence to convince authorities their marriage was genuine.