When showing the "assassin expression" to the audience at the beginning of the episode, Dr. Lightman claims that the third picture belongs to "a Basque separatist, getting on a bus with 20 pounds of explosives strapped to his chest". Basque terrorists never do suicide attacks.
The Secret Service is involved in this story and this makes sense because it protects foreign ambassadors. However, there are also references to the Treasury Department, which makes no sense because the Secret Service is no longer part of Treasury. It was transferred to Homeland Security several years ago.