Sejanus was tasked with interrogations of subjects. He threatened them with death unless they recanted. After the death of Pepin VI, Sejanus arrested his widow, Berengaria. As he escorted her to the jail, he accepted a bribe from Childeric, allowing him to speak with his mother.
As part of Pepin VII's initiation, Sejanus raided the king's quarters and fired a gun at him as a test of his immortality. Pepin survived as it fired blanks.