The relative "lateness" of specifying the tomb of Catulus as the site also depends on the dating of one of the other sources on the killing, the Commentariolum petitionis, an epistolary pamphlet traditionally attributed to Cicero's brother, Quintus, but suspected of being an exercise in prosopopoeia by another writer in Imperial times.Such a writer would have been creating a persona based on Cicero's speech In Toga Candida, and thus the Commentariolum might still preserve accurate details not found in Asconius; see Damon, "Com. Pet. 10," p. 282, note 5. The epistle presents itself as having been written in 64 BC by Quintus for his brother during his candidacy for the consulship;"Here it must be recognized that there was no question of Marcus needing his brother's advice on electoral campaigning," notes Andrew Lintott; for a discussion of the Commentariolum in relation to the elder Cicero's speech In Toga Candida, see Cicero as Evidence: A Historian's Companion (Oxford University Press, 2008), p. 130ff. online. if authentically the work of Quintus, it would be contemporary with Cicero's own account of Gratidianus' death, and provide a kind of "missing link" in the narrative tradition. The Commentariolum says that Catiline
