Prosecutor Misconduct in Florida and Arizona

Today's USA Today and Arizona Republic describe serious and probably intentional errors made by US Federal prosecutors in court cases.
In the USA Today article, Businessman Nino Lyons spent three years in jail after a prosecutor hid evidence that would have exonerated him. The judge who finally released Nino Lyons, declared him innocent. However the prosecutor was only required to attend a one day ethics class as his punishment. The prosecutor ruined a mans life, sent him to prison for 3 years, all the while knowing that he had bribed false inmate witnesses to testify against Nino.
In the Arizona Republic article, A federal judge found Tommy de Jong, a Buckeye dairy farmer, not guilty of felony pollution charges. The judge ruled that U.S. attorneys continued their prosecution despite knowledge of de Jong's innocence. De Jong was reimbursed for his legal costs. The article also said that there have been 201 criminal cases since 1997 where judges determined that U.S. Justice Department prosecutors violated laws or ethics rules.

One of the problems is that the only solution for errors made by prosecutors is to sometimes let a guilty person go free. Again, the prosecutor never appears to be tried or punished for the crimes committed while prosecuting the criminal. Yes, prosecutors need to be protected somewhat in order to do their job. They do need additional powers because the criminals will try everything they can too. However the "win at all cost" actions done by prosecutors needs to be held in check. Right now there doesn't appear to be any method of holding Federal, State or County prosecutors accountable for intentional misconduct.