Those incidents usually don't get reported. In a situation where its your word against a cop's, the cop is always given preference. I can honestly say that I don't think I can remember reading a single "bad cop" story that didn't have video evidence

Did you read the article? David Simon, the author, talks about such incidences.

I think this qualifies:

http://www.injusticebusters.com/04/Diotte_Kerry.shtml

It's only one story, but it includes lots of bad cops. One newspaper reporter. And no video.

Yes, there was an overheard conversation on the police radio. But that was 'hearsay' evidence. Not something that was copied (at least to my knowledge).

Edit: NO, it doesn't qualify. The conversation was recorded. Thanks for making the point.

OK, but if a video exists, no newspaper is required. YouTube is sufficient.