All-Star Western Vol. 01 - Guns and Gotham (2011) (Digital TPB)

Even when Gotham City was just a one-horse town, crime was rampant--and things only get worse when bounty hunter Jonah Hex comes to town. Amadeus Arkham, a pioneer in criminal psychology, enlists Hex's special brand of justice to help the Gotham Police Department track down a vicious serial killer! Collects issues #1-6