Yes he can. Sometimes a pope does not even have to sign anything. He can create canon law by signing a motu proprio - Sacramentorum Sanctitas Tutela. He can also direct a cardinal to sign an Instruction - Secreta Continere . The law is normally promulgated by publication on the Acta Apostolicae Sedis, but it doesn't have to be if the pope directs otherwise - Crimen Sollicitationis. The pope has no restraint on him by a parliament, Supreme Court or Constitution. All legislative, executive and judicial power resides in him. There is no appeal from his decrees,  and he is judged by no one. He is the last of the absolute monarchs. He is only restrained by Scripture and Tradition, and in the latter case, tradition for 1500 years until 1917 required sex abusing priests to be handed over to the civil authorities. He can direct mandatory reporting by creating an exception to the pontifical secret in Art 30 of Sacramentorum Sanctitatis Tutela, restoring that tradition.