Is a professional police force necessary?

via Lew Rockwell blog:

Police and Thieves

In the comments to that blog entry, one finds the following: ARE COPS CONSTITUTIONAL?
(I don't think the author successfully shows that the establishment of professional police forces is against the letter of the Constitution; he tries to show that the consequences of their creation are predominantly harmful to a "republic." After all, their creation was something undertaken at the local level, not the Federal level. Perhaps there might be a coherent argument against the FBI being constitutional. I doubt it.)

What sort of solutions do paleolibs have to the two causes that necessitate the creation of a professional police force?
1. Big cities (and the crime rates that go with them).
2. Extreme differentiation of function because of the demands of the political economy.

It will be difficult for city-dwellers to help enforce the law if they are busy working 9 to 5, and have "family" obligations afterwards. If professional police forces are an "evil" (that is, lead to evil consequences or conditions for the political community), the author has not shown they are not necessary evils.

Perhaps if the police were unarmed the author would be more sympathetic--but the conditions that would permit an unarmed police force don't obtain here in the U.S., as they no longer exist in the U.K.