The law is an excerpt from the Sirmondian Constitution 6, just like 16.2.47, 16.5.62, 16.5.63, and 16.5.64. 16.5.63 is dated to 6 August 425 and is directed to the pretorian prefects of Gauls. See Delmaire 2005: 215.
The "tyrant" mentioned in the law is the usurper John who raised to power in Rome in 423-24.