David Shannon was an engineer for Gotham Optics, and a murder victim.
Sometime during Christmas Eve, David Shannon was dispatched to repair a faulty network tower at the Coventry Tower. Unfortunately for him, when he was about to access the tower controls to repair them, the keycard scanning device had exploded, killing the hapless technician by throwing him across a wall into the adjoining room. The scanner had been sabotaged by John F. Baker, a low-level thug hired by Enigma to ensure no one attempted to access the network tower that Enigma had sabotaged. Batman, having arrived at the tower sometime later to take care of the sabotaged network tower to allow his Batwing to fly over to the Bowery District to uncover the location of the Penguin, uncovered the murder and proceeded to solve it, also using the codes included on the discarded keycard to hack into the panel via his encryption device to evade the booby-trapped panel, although he wasn't able to apprehend the criminal responsible, learning that Baker had himself been murdered in the Diamond District (presumably by Enigma, to cover his tracks).