I'd say that you are on the right track. From my reading it seems like you are most likely not a native english speaker, as I noticed a few idiomatic issues, but I don't think that's anything that is going to be an easy fix in just a couple days. I think that, for the most part though, you've touched on a few of the main issues, namely the fact that the argument is a really superficial view of the problem, and doesn't look at addressing the underlying causes for the problem.
My personal opinion, however, is that you would be well served to find some common ground or understanding with the argument that is layed out. In this case, I think that there is an argument to be made that, if crime is going crazy, you do need extra police to help in the immediate future. This doesn't solve the long-term problem, but you still need to do something short term. I like the fact that you point out that "doubling" the police force is just an arbitrary number. Why not triple it, quadruple it, etc? So I like that you hit on that item. I think that showing that you are capable of seeing more of where the other side is coming from in the argument will help add to your essay, however.
For instance, if it was me, I would have said something like "I understand where the author is coming from, but I feel he/she is overlooking a few major considerations. While I understand the need for increasing the police force in the short-term, it is perhaps more important to look at the underlying causes for crime in the community"
That way you acknowledge the other side and their point of view, showing you are capable of analyzing both sides of an issue, and then you pivot to your true argument.
That's just my advice though, and may be totally off base. Hopefully that at least helps a little bit.