Five police officers in Miami recently attacked two men while thirteen of their fellow officers watched. [1] The idiom "bad apples" comes from the saying, "A few bad apples spoil the whole bunch," so it's an appropriate term here.
And only charged with misdemeanor "battery" without any enhancements. Had the perps not been police it would be multiple felonies + enhancements for things like gang activity and firearm possession. Looks to me like the DA does not want to upset the police and their unions and is only doing the very minimum to make an impression that he is working.
[1] Video footage: https://www.youtube.com/watch?v=gF4ze5VCY1c