The Ending (final scene) Possible Spoiler Alert
Maybe I missed something in the final scene, but was the guy in the end with the mask the cop shot, the exact killer he had been chasing? The masked guy seemed to have his gun, glued to his hand, and revealing part of the mask, really didn't say for sure, who it was.
Outside of that, I really loved the movie, the whole concept was original for a crime thriller, and it held my complete attention from start to finish. 8/10 for me.