Detective Comics, Vol. 1 #779 (2003)

Dead Reckoning, Part Three; Spore, Part Four
Following the Penguin's latest steps, Batman manages to track down a lead on the mysterious murderer plaguing Gotham's costumed villains. He learns that the murderer is Paul Sloan, a theater actor who was known for immersing himself deeply into the roles he took on. Now, Batman has to find this master of disguise before he claims another life.
Release Date: 2003