You were doing pretty good until you stuck that 'truthful' in there. Eric Holder's InJustice Department isn't looking for truthful testimony. They want testimony that supports their racist agenda.
I think the DOJ has pulled a Pontius Pilate on this case and it is in the hands of St. Louis County to carry the ball the rest of the way. I believe Dorian Johnson was brought forth to the Grand Jury and told the truth in exchange for not being charged with some crime, perhaps Murder Second Degree if he helped assault Wilson.