Corrected entry: When the cops at the shooting range are showing the, "cop killer" bullets, they shoot through a bullet proof vest, both sides. At the end of the movie Rene Russo is shot with a cop killer bullet, but it does not kill her because she is wearing two bullet proof vests. This would not stop a cop killer bullet. It had already been proven to go through two layers of kevlar, not to mention the bullets go through the thick steel of the bulldozer blade.
Soylent Purple
6th Jul 2006
Correction: In the movie, the vests are much thicker in the front then in the back. The bullet didn't have the power to penetrate the double thickness of the front armour. So the bullet only went halfway through the front of the second vest.
Soylent Purple