Shoot through walls
When you are chasing Steve Houstown for metal fences that are taller then you and have a building that in beside it, go up to it and hold R1 and you may or may not target an enemy thats on the other side of the building around the corner. If the target is green, orange, or red. Start shooting only if the target is one of those colors, and it will actually hit the enemy and kill him if you keep shooting.