After pausing the game, enter code
Code: push R1, Circle, R1, L2, R1, L1, Square.
When you first start the FBI level, immediately after the woman shoots out your cuffs, go to the center of the room with the three computers. You will find the Ubisoft logo acting as a screensaver. If you walk up to the computer screen, look down at it, and press X, the screen will say GAME OVER.
9mm Handgun - Can shoot 13 shots before you have to reload, you can carry two guns at a time, and 2-3 shots usually kills an enemy. 44 Special - One head shot kills an enemy but only has 6 shots before you have to reload. Shotgun - Good for up close shooting and can cut through body armor in most enemies. Simple Crossbow - you must reload...
In the level with the lifeguard that gets shot after you get the throwing knives, kill an enemy. Then, start stabbing the dead body. Little drops of blood will appear.
Wait until an enemy reloads his weapon before killing him. Kill him before he fires his gun and you will get a full magazine for your weapon.
In the beginning of the game, run though the back door to a gun faster and safer than going to the man at the front.