“Suspect Tashfeen Malik passed DHS counterterrorism screening as part of her vetting for K-1 visa”
No more K1 visas for these people since they can not be vetted and NO SO CALLED SYRIAN refugees.
K-1 visa is one of the easiest visa to get, even easier than tourist visa.
They were married but applied for K-1 visa. US embassies ignores this factor, because that is lie/fraud/misrepresentation.