I'm skeptical, especially of the surveillance claims. If you already know who you're looking for and you have lots of footage of that person, you might be able to train your system to pick up that person's gait from new footage. But that's a far cry from being able to "identify anyone" by their gait, i.e. set up lots of cameras around the city and track individuals coming and going.
There are already amazing airborne camera systems that track the motion of every license plate in a city, and even that isn't the same as tracking every car's movement because you still have to know which license plate to follow -- you just can't care about all movement of all cars. I suppose someone will say that you can store all movement in a database, but I'll wager that's just not worth anywhere near the cost. Your computing power would be much better spent on computing large primes.
Anyway, it's a cool sci-fi movie premise. You can see the murderer shaving off his mustache, burning off his own fingerprints and then knee-capping himself to avoid detection.