These ones pop up in EVERY level but mostly randomly. (They occur most often in Pelagic II at random.) Here's a way to always get one. Air Base: Espionage, no cheats required. There's a security thing that's upstairs, near a glass wall. BEFORE that, there should be a guard in white wandering around. The thing you have to do is activate the switch and QUICKLY get downstairs before the guy vanishes. If done correctly, he should take out a few soldiers and then one of the NSA lackeys will turn blue as though you psycosed him. Or, it might actually be the white guy who does... You can try luring the white guy towards the stairs to make it easier.
Submitted by: AndyDark