The P90 is a Belgian-made submachinegun that fires the armor-defeating 5.7mm round.
Kane & Lynch: Dead Men
Kane is the default user of the P90. It only makes a short appearence in singleplayer, with it being in the Tutorial, Withdrawal and the Chase scene.
The weapon is available to buy in Fragile Alliance for $ 30,000. Since it is the cheapest gun it is often overlooked infavor of the M4 and SIG 552, but it has the least recoil out of any of the primary weapons making it deadly in the hands of a skilled player