Two good links discussing the the militarization of the local law enforcement. The first article titled, Obama Stimulus Program Includes Billions for Cops", covers how the 2009 Stimulus package had items to help increase funding for local law enforcement officials:
"The grants are popular with Democrats, and restoring them was central to Obama's campaign plan to combat rising violence. By tacking the money onto the stimulus plan, Obama avoids having to defend the spending during the normal budget process."
Yet, crime rates, according to Cato Research Fellow Trevor Burrus, have been declining since the 1990s. He makes this point and other points regarding the funding of local law enforcement in this Cato Podcast: