Final answer:
In Sophocles' play, a witness confirms that Laius, King of Thebes, was killed by bandits at a crossroad while traveling.
Step-by-step explanation:
In Sophocles' play, the one thing a witness says is known about the murder of Laius, King of Thebes, is that he was killed by bandits at a crossroad while traveling.
This is revealed when Oedipus asks if anyone is left from the group that was with Laius during his trip, and it is discovered that a shepherd was present at the time of the murder.