One of the two Praetorian Prefects , Tarrutenius Paternus , had actually been involved in the conspiracy , but was not detected at this time . In the aftermath , he and his co-Prefect Sextus Tigidius Perennis organised the murder of Saoterus , the hated chamberlain . One of the two praetorian prefects , Tarrutenius Paternus , had actually been involved in the conspiracy but was not detected at this time , and in the aftermath , he and his colleague Sextus Tigidius Perennis were able to arrange for the murder of Saoterus , the hated chamberlain .