The ironic thing about this movie
Didn't the precogs system actually work and it got shut down anyway?
I mean theres 3 ways it wont work, 1) if someone on the inside manipulates it by faking the murder and exploit the echo getting diregarded to commit the murder for real, 2) future murderer having a choice since he knows his future(which by the way originates from the system working, and 3) minority reports.
You could more or less easily fix 1) and 3) by not having a psycho as the chief and by taking extra care for the few minority reports that will happen, and the situation 2) will never happen in normal cases.
So yeah, the system would have worked perfectly with some easy fixes and yet got shut down for good.