To get the special costumes you must do the following.
Start a new game on normal difficulty. Don't pick up anything. When you get to the gate that leads to the police station go down the stairs. Down there will be Brad Vickers, the pilot from Resident Evil (he's a ZOMBIE!) Head past him and go up the stairs. Get the herb from the bushes closest to the stairs. Go in the R.P.D. and get the bullets at the desk in the back of the room. Go back to Brad and fill that damb zombie full of bullets. Inspect him and take the special key.
When you get to the dark room there are some lockers, use the key to unlock one and get the costumes. With Claire you get a cool denim jaket and the Colt S.A.A. gun. With Leon you either can choose a leather jacket with a skull on the back or a tank top and a baseball hat.
Note: The quickest way to kill Brad is to get close then walk backwards. Let him lunge at your feet then stomp him in the head. This saves a lot of bullets and only takes away 1/8th of you health.
To get the special costumes you must do the following.
Start a new game on normal difficulty. Don't pick up anything. When you get to the gate that leads to the police station go down the stairs. Down there will be Brad Vickers, the pilot from Resident Evil (he's a ZOMBIE!) Head past him and go up the stairs. Get the herb from the bushes closest to the stairs. Go in the R.P.D. and get the bullets at the desk in the back of the room. Go back to Brad and fill that damb zombie full of bullets. ...
If you finish the game in 2 1/2 hours or less on mission A and get a rank of A or B, you will get the rocket launcher with infinite rounds.
On Mission B you have two options: If you finish the game with an A or B ranking and under 3 hours, you'll get infinite sub-machine gun. If you finish the game with an A or B ranking in under 2 1/2 hours you will get infinite rocket launcher sub-machine gun and the almighty gatling gun.
Submitted by Marcus
Play the first scenario with either character. Enter your finger print on the computer in the giant moth room. When you get to the door where you need your finger print to enter, enter your finger print and choose not to continue. Finish the game and save. Play off of the game you saved with the next character and follow the same process and put in the second finger print. The door will unlock and inside will be a few Lickers and a sub-machine gun.