Grand Jury Tampering

Justice Scalia Explains What Was Wrong With The Ferguson Grand Jury | ThinkProgress:

...In contrast, McCulloch allowed Wilson to testify for hours before the grand jury and presented them with every scrap of exculpatory evidence available. In his press conference, McCulloch said that the grand jury did not indict because eyewitness testimony that established Wilson was acting in self-defense was contradicted by other exculpatory evidence. What McCulloch didn’t say is that he was under no obligation to present such evidence to the grand jury. The only reason one would present such evidence is to reduce the chances that the grand jury would indict Darren Wilson...