used, standard counterintelligence investigative approach to take a large pool of individuals and weed it down to some likely suspects and doing so, we were able to identify brian riggien. >> so you did capture him before he actually left the country, right? and the plan was or his plan was to approach foreign leaders personally but then this operation, even trying to pursue him, was a national security risk. to what degree? >> it was a national security risk mainly because he had access to some of the most sensitive information and what we were try iing to do is limit not only his ability to capture that information from our systems, but to actually make contact with another adversary and what we had to do was closely watch him. at the time, the tools in place to do so weren't exact and they weren't perfect so we really had to do our best to ensure that we had to catch him in the act of