Given the way the president would be investigated and tried, it's almost impossible to even begin collecting evidence or following any leads. The only reason Operation Lava-Jato was able to start investigating Lula is because he was no longer president, but he gained immunity when Lula was appointed Dilma's chief of staff.

https://en.wikipedia.org/wiki/Luiz_In%C3%A1cio_Lula_da_Silva...

There is at least enough proof that Dilma went out of her way to end a lead in investigations that would have led to her if she is/was involved.

I was doing some research on Pasadena case, and found this

https://www.google.com.br/url?sa=t&source=web&rct=j&url=http...

I believe he is talking about the Pasadena case, that was a really strange deal and a lot of people condemned back there.