Who does Oedipus believe can prove him innocent of the murder of Laius?

Oedipus believes that the shepherd who witnessed the murder of Laius can prove him innocent because this shepherd possesses critical knowledge about the events surrounding the murder. In the narrative, the shepherd is a key figure who can provide testimony about what really occurred, specifically concerning the circumstances of Laius's death and Oedipus's connection to it. As Oedipus investigates the truth of his past and seeks to clear his name, the shepherd's insights become crucial to unraveling the mystery and confirming Oedipus's innocence in the eyes of the Theban people.

The other options pertain to significant characters or sources of information but do not offer the same direct connection to Oedipus's innocence regarding Laius's murder. The messenger from Corinth primarily brings news that complicates Oedipus’s understanding of his identity rather than clarifying the murder; Jocasta, although she is closely tied to Oedipus, is unaware of the full truth about Laius's death; and the oracle of Delphi, though a source of prophecy, does not provide the specific eyewitness evidence that the shepherd possesses. Thus, the shepherd stands out as the one Oedipus believes can definitively prove his innocence.