Eugene Keelson was a man capable of getting any kind of information on anyone but for a price.
He was also responsible for jeopardizing the Office of Special Projects's computers and as such, the virus he launched against the system granted him access to the files on numerous NCIS Agents and their operations which he presumably planned to sell on the black market.
OSP were successful in stopping Keelson but Callen was forced to kill him when Keelson raised his gun.
- Michael St. Paris- (intentionally ran over to cover his tracks).
- G. Callen- (attempted).