Tashfeen Malik passed background tests for K-1 visa. What the media is getting wrong is that the visa application process in Pakistan, like everywhere else, is OUTSOURCED out to foreign national contractors!! From the U.S. embassy in Islamabad: "The Embassy and Consulate General of the United States of America in Islamabad and Karachi, Pakistan will transition to a new appointment and document delivery service for the non-immigrant visa unit as of August 24, 2014. This new system, which is being implemented in phases at U.S. Embassies and Consulates worldwide, is designed to be more comprehensive and user-friendly. It replaces the current appointment system of scheduling at Amex and Speedex locations in Pakistan, though these contractors will also be involved in the new system."

http://www.foxnews.com/us/2015/12/13/tashfeen-malik-reportedly-passed-background-checks-despite-questionable-social/