campbell robertson, thank you for being with us.hat would you add to the account we just shared about the prosecution's case? you wrote that it was a grisly account. i believe that was your word. >> well, this account started coming out over some time. there had been five police officers who pled guilty, some of whom were actually firing at the bridge that day, other ones who were involved in the coverup, one of them described as a massacre. so, as those guilty pleas were coming out, the, while everyone knew this was, everyone had suspected that this was a very bad scene, the grislyness of it began to come out one at a time with those guilty pleas. so when the prosecutors finally put it altogether, it was a pretty harrowing account of what happened that day. >> woodruff: and there were accounts of the police tampering with the evidence, planting a gun. tell us a little about that part of the prosecution's case. >> well, it's funny, the coverup, the prosecutors say the coverup began immediately at the bridge. there were officers said