During a holiday event on December 2, 2015, Syed Rizwan Farook and

his wife, Tashfeen Malik, entered the San Bernardino (California) Inland

Regional Center and opened fire on those in attendance. The couple

killed 14 and wounded 22.1

A health inspector for the county, Farook had been

in the building earlier that day for a meeting, but left before the party. He

came back later, this time with Malik. Both donned ski masks and tactical gear

and were armed with semi-automatic pistols, rifles, and explosives. They fired

upward of 75 bullets over a four-minute period and left before police could

arrive at the scene. Farook and Malik also left three explosive devices behind,

which authorities believe they were designed to target first responders, but

fortunately they did not detonate.

Police arrived shortly after the couple fled. Having recognized his voice and

build, a witness identified Farook. Thereafter, officers learned that Farook had

rented a black Ford Expedition SUV with Utah plates four days before. A few

hours into the investigation, and based on a tip from a neighbor, police went

to Farook's home in nearby Redlands. The Expedition was seen leaving the

area, and officers gave chase. Farook and Malik were soon stopped, whereupon

they exchanged gunfire with police and were killed.2

In the aftermath of the shooting, speculation abounded as to the causes.

Some said a workplace dispute prompted the shooting. Others said the motive

was terrorism. Unfortunately, the latter was true; the investigation revealed

that both Farook and Malik were "homegrown violent extremists" who had been

inspired by foreign terror groups.3

They had been radicalized as early as 2013

and, according to (then) FBI Director James Comey, "were talking to each other

about jihad and martyrdom" even before they were engaged.4

The couple used

social media to pledge allegiance to the Islamic State shortly before they were

killed by police. Neither Farook nor Malik had criminal records and were not on

any terror watch list, making it especially difficult to predict that they would

perpetrate such an atrocious act.

What was the motive of the shooting? How could their shooting have been prevented?