The alleged crime seems to be that some classified documents were found on his mistress's computer. She probably shouldn't have had them, so the question is, how did they get on her computer?
When the government lacks credibility anyway -- so much of what the Obama administration does is political -- it's hard to trust them on this.
We know that federal agents can put things on people's computers without the owner knowing about it. Ask Sharyl Attkisson about that. As for her take on Petraeus, she excerpts passages about him from her book here.
Meanwhile, another controversy is waiting to boil over within the Obama administration: a sex scandal involving the CIA’s Petraeus. The timing is—intriguing. Only after the Benghazi attacks, as Petraeus’s loyalty to the administration falls into question, does everything turn sour for the spy chief.
We should be learning more about the government's tampering with Attkisson's computer as her lawsuit proceeds.