They were, with an overwhelming amount of evidence of several different wrongdoings.

Just to point, he was tried for 2 different crimes, by 4 different judges each, and found guilty every time.

> In the end all of the major charges against Lula were annulled

By those same political judges the GP is talking about. Based on the trial not following a law that was created 2 years later, with the explicit intent of making trial of politicians harder.

> and the charge that got him sent to jail was a political character assassination job

And that's, to be blunt, absolute bullshit. The charges were never formally decided after the trial was annulled, they are still open, sealed back into secrecy, and pending judgement.