He wears a belt full of working tools, is a master of secrecy and owns a tuxedo – but let’s be honest, that evidence is anecdotal at best. However, I submit to you that the Dark Knight is in fact a Freemason, and here is the proof.
Exhibit A. Legends of the Dark Knight #86 – 88 (1996) is a three-part mini-series called “Conspiracy” in which the Caped Crusader investigates a series of murders with loose ties to Masonic legend (amongst the legends of other secret societies). Of all the various murders, Batman immediately recognizes a pattern in three cases and contacts Alfred to confirm his suspicions.