Another focus of my investigation was the Pakistani women’s Islamist group al-Huda, which counted Farook’s wife, Tashfeen Malik, as a student. While the al-Huda International Welfare Foundation distanced themselves from the actions of their former pupil, Malik’s classmates told the Daily Mail she changed significantly while studying at al-Huda, gradually becoming “more serious and strict.” More ominously, the group’s presence in the U.S. and Canada is not without its other ties to ISIS and terrorism. In 2014, three recent former students at al-Huda’s affiliate school in Canada, aged 15 to 18, left their homes to join the Islamic State in Syria.

We had these two groups in our sights; if the investigation had continued and additional links been identified and dots connected, we might have given advance warning of the terrorist attack in San Bernardino. The combination of Farook’s involvement with the Dar Al Uloom Al Islamiyah Mosque and Malik’s attendance at al-Huda would have indicated, at minimum, an urgent need for comprehensive screening. It could also have led to denial of Malik’s K-1 visa or possibly gotten Farook placed on the No Fly list.

But after more than six months of research and tracking; over 1,200 law enforcement actions and more than 300 terrorists identified; and a commendation for our efforts; DHS shut down the investigation at the request of the Department of State and DHS’ own Civil Rights and Civil Liberties Division. They claimed that since the Islamist groups in question were not Specially Designated Terrorist Organizations (SDTOs) tracking individuals related to these groups was a violation of the travelers’ civil liberties. These were almost exclusively foreign nationals: When were they granted the civil rights and liberties of American citizens?