The Three Ghosts of Batman were created by Grant Morrison. They were a resurrected plot from former Batman comics.
The Ghosts were a product of a collaboration of the Gotham City Police Department and Doctor Hurt. It was a time when the Gotham PD became worried of the day when Batman would disappear. All this happened under a different Commissioner, hence only a few officers had know what transpired.
While Doctor Hurt was assisting Batman in an experiment regarding Space Isolation he introduced the Gotham PD Batmen. At the time Batman thought these other Batmen were possible futures, which he coined as Three Ghosts in his Black Case Book, and beat them to a pulp.
The Batmen project was shelved but the Three Ghosts had been damaged and were given severance from Gotham PD. Still they remain sleeper against just waiting for the "Bat-signal in their heads" to light up.
Batman with a Gun
Josef Muller was a cop coined as an ace marksman. He simply wore a Bat-suit and carried a gun. When the he faced Batman in the isolation chamber, Batman broke his hands.
He was the first of the Ghosts to re-surface. Joker thinking he was the Batman, beat him close to death until the real Batman intervenes.
He shoots Joker and is never heard from again.
Officer Branca was a family man who followed orders. He allowed Doctor Hurt to inject him with Venom and all sorts of drugs. He later kills his family and subsequently locked up in a bathhouse.
He resembles Bane which strikes a deep-seated fear in Batman. He is shot by Officer Farelli at the close of Batman: The Black Glove.
Michael Washington Lane was a young cop that was made to suffer the same psychological trauma as Batman. Supposedly he was the worst of the three Ghosts and future blight on Gotham City. In an alternate future, with Damian as the Batman, Lane would resurface and claim that he had made a deal with the devil.
After the events of Batman: The Black Glove, Lane is the only Ghost of Batman that becomes a recurring character. He is seen assisting Doctor Hurt in Batman: R.I.P. and is shown to show remorse for his actions during Batman: Battle for the Cowl. He would later take the mantle of Azrael.