Little is known about 26-year-old Pakistani national Tashfeen Malik, other than she was able to enter the U.S. on a fiancée visa, also known as a K-1 visa, allowing foreigners to travel to the U.S. for a wedding within 90 days.
Malik married 28-year-old Chicago-born husband Syed Rizwan Farook two years ago in Saudi Arabia after the pair met online, according to a family member and a friend. The couple — who had a six-month-old daughter — were both killed in a shootout with police following the rampage in which 14 people were shot dead.
A high-ranking official at the Interpol section of Pakistan's Interior Ministry told NBC News that "Pakistani authorities are in touch with Homeland Security" in a bid to trace details about Malik.
Speaking on condition of anonymity, the source said details sent through by the U.S. were scant so far but confirmed that "the work has started."
The official added that until Pakistani officials had "a picture, or an ID card number, or a passport number, we can't follow any leads."
A senior member of the Federal Investigation Agency, which is Pakistan's FBI, said that it would not be "an easy search" for authorities. The source added: "We will need more data to get more data, if only because our systems are not that sophisticated."
The K-1 visa program has one of the more rigorous security screening processes — presenting far more hurdles than other avenues for foreigners to enter the U.S.
Wajahat S. Khan
Wajahat S.Khan is a correspondent and producer for NBC News based in Islamabad, covering South Asia and also assisting the Kabul bureau. Khan is the national security correspondent for Pakistan's largest news network, Geo, and its largest English newspaper, The News.
He was the first Pakistani Fellow at the Shorenstein Center for the Press, Politics and Public Policy at the Harvard Kennedy School of Government.
Previously, Khan reported for CNN, and contributed alternative-media reportage to San Francisco-based Link TV. He anchored a popular investigative series on Pakistan’s local Aaj TV, and also hosted and produced for Pakistan’s first English-medium network, Dawn News.
He is also the first broadcaster from Pakistan to produce an investigative series from across the “divide” in India. Khan has written for most of the major Pakistani publications — The News, The Dawn, The Express Tribune, The Friday Times and The Herald, and also contributes to India Today, India's most popular weekly.