Credit

where credit is due? DOJ investigating police departments

Seems reasonable. There are about a dozen other reasons I can think of for investigating police other than brutality or blatant racism against minorities, but that is a pretty good one on its own for a start.If for no other reason than Sheriff Joe may get a day in court instead of a day in the Senate (yes, Arizona really is that stupid).

To wit I recommend any of the following in addition to the announced premise:
Overuse/deployment of SWAT, especially for no-knock raids on non-violent offenses. In related story, increase training of police to deal with pets (dogs especially) in any way that does not include automatically shooting them. Sometimes, unfortunately, necessary, but not in most cases that it actually happens. The militarized mindset of some police has made it rather difficult to distinguish between hostiles and neutrals and even friendlies it seems.

Punishment of whistleblowers (eg, being fired or put on desk duty and ostracized) should cease. Of course, I wouldn't rely on the Obama administration to be putting this one very high on its list....

Increased power for civilian review boards, especially where violence or abuse of civil liberties are involved. Between this and the ACLU, reigning in some of the most egregious abuses should be possible at least.

Increased reliance on civilian transparency (video/audio recording of police committing possible infractions) or police transparency (self-recording of civilian infractions).

Decrease the reliance on drug war funding. Force cops to go back to real police work instead of engaging in an wasteful open war with some of the cities constituents. Investigating murders and violence and robberies and such is one thing, and a very decent thing to do even in territory of drug gangs. Contesting "their" control over such areas the way it is commonly done is liable to end up with more violence (see Jamaica, Brazil, etc).