The futility of vetting immigrants to prevent terrorism

Earlier this week, ABC News reported that federal agents interviewed Sayfullo Saipov in 2015 but never opened a case against him. Saipov went on to kill eight people in a vehicle attack on the West Side of Manhattan.

Saipov was listed as a “point of contact” for two men whose names were in a Department of Homeland Security counterterrorism database and who later overstayed their tourist visas, according to a federal official. One was flagged after arriving from a “threat country,” while the other vanished and was being actively sought by federal agents as a suspected terrorist.

This is a familiar story.