You shall understand what hath befall’n, 3608 Which, as I think, you know not. Here is a letter 3609 Found in the pocket of the slain Roderigo, 3610 And here another.
"By this point, Othello has been manipulated by Iago into killing Roderigo and Cassio, and Lodovico’s arrival brings the Venetian authorities into Cyprus. Lodovico’s statement is meant to clear Othello’s name and show that the violence was the result of Roderigo’s and Iago’s schemes, not Othello’s own will"