NCIS: Los Angeles Season 2 Episode 8 (11/09/10)
The team investigates the killing of an Army special forces officer who just retired.
The day he became a civilian, he was going to return to Afghanistan and track down a well-known Taliban bomb maker to collect the reward.
He met his end at the hands of a guy looking to do the same, however. Kahn had diplomatic immunity and was basically ratting out high-ranking terrorists to make a living. The government new about it and saw it as a means to an end.
The team eventually tracked down a message the deceased soldier, Booth, sent to his son with the location of the bomb maker encoded. He gave faulty tip to Kahn and the team went on location to capture the bomb maker AND the bounty hunter.