I just rented the movie and I hadn't heard about it before. It's nice to see some quite realistic yet action-packed shootout. Notice that you can actually see the bullets making holes in walls (you don't even see that in most Hollywood movies since they seem to think bullets will just bounce off brick-walls...). Some quite good acting and a complex yet sense-making plot (if you can't understand it, watch it again or wait until you've finished high-school..).
You see a quite capable SWAT-team slowly getting decimated all the while hunting a psychotic killer who seems to be constantly hiring new thugs for support too. Most of the background story unfolds only in the end but it makes sense and the tension generated stays fresh throughout. Good work.