Boratio appears to be overcome with an attack of conscience upon hearing of Hero's supposed death. Whether his guilt is truly remorse or merely an attempt to save his own life is up to the reader to decide. Nonetheless, Boratio does come forward and accept responsibility for it. After confessing, he asks Don Pedro to allow Count Claudio to kill him for his crime, and explains that his confession was most likely overheard.
Boratio attempts to take all the responsibility for Hero's death, instead of trying to shift blame away from himself in an attempt to spare his life. Leonato does not allow him this, stating that Claudio and Don Pedro were also guilty of the crime.