” ...you dont have to be charged, indicted, tried and found guilty to end up in front of a judge for sentencing.”
I’m not a lawyer, but at a minimum it would seem that you have to be charged (or “indicted”) for a crime in order to be allowed to plea guilty to it! In any case, this article from Politico (I know ...) indicates that Gen. Petraeus *was* indicted.
http://www.politico.com/story/2015/04/david-petraeus-sentence-classified-information-117290
The evidence against Petraeus was never presented to a grand jury. Here’s what happened.