Start an A Scenario with either Leon or Claire. Start the game, but DON'T COLLECT A SINGLE ITEM. Don't collect the weapon in the Gun Shop, any ammo. Go to the Police Station and down the stairs in the courtyard. A zombified Brad will be there. Kill him one way or another (by collect ammo in the RPD or stabbing him). Collect his ''Special Key'' and take it to the RPD Darkroom. Open the locked by the door and you get new costumes!