Fallen is correct. The aiming style in RE0, RE1, RE2, RE3, and RE:CV are the same. The camera is set to fixed spots some where in the room, which doesn't allow you to aim for specific spots on an enemy.
RE4 and RE5 are different from the rest because it's camera is set to show over the shoulder of the character; therefore, allowing you to aim at specific points on the body of an enemy.