Poindexter is best known for his role in the Iran-contra scandal, in which the Reagan administration illegally sold arms to Iran and used the proceeds to illegally fund the Contra rebels, and then illegally covered the whole thing up --- the coverup continuing into the Herbert Walker Bush administration. Notably, they were selling arms covertly while publicly trying to make Iran a pariah state. Poindexter was eventually convicted for his role in the sales and coverup.
But the conviction was overturned when an appellate panel ruled that special prosecutor Lawrence Walsh couldn't prove that his team had never taken notice of Poindexter's testimony before Congress. (It wasn't enough that Walsh had never used the testimony in court, as part of his case --- the standard was that he and his team couldn't even see it, which was impossible, as it had been widely covered in the press).
So, defenders of Dubya, take heart --- the head of the Information Awareness Office may, in the past, have masterminded a coverup , but he is not, repeat not, a convict.