This is obtained on the 2nd Mission Piccadilly. You need to get a kill in 4 locations, both subway undergrounds, the reading place, and aural chic. Make sure to get in these locations and get a kill quick so the cops dont steal the kill or the enemies run out. Also the subway to the right can be a little tricky. Make sure you get the bomber running at you down the stairs, he needs to die before the bomb goes off for this to count.