The Mishnah taught that they did not condemn witnesses as perjurers until other witnesses directly incriminated the first witnesses. Thus if the first witnesses testified that one person killed another, and other witnesses testified that the victim or the alleged murderer was with the other witnesses on that day in a particular place, then they did not condemn the first witnesses as perjurers. But if the other witnesses testified that the first witnesses were with the other witnesses on that day in a particular place, then they did condemn the first witnesses as perjurers and executed the first witnesses on the other witnesses' evidence.