Batman the Killing Joke cover
"Batman: The Killing Joke" comic coverdccomics/facebook

Comic Book has reported that Alan Moore and Brian Bolland's critically acclaimed graphic novel "Batman: The Killing Joke" has topped Neilsen BookScan's Top 20 Adult Fiction Graphic Novel chart.

According to the website, the 1988 graphic novel is one of the Top 20 and continuously rose up the charts. It seems sales of the novel have seen a significant boost after an animated adaptation of "Batman: The Killing Joke" was announced, to be released next month, and David Ayer's "Suicide Squad" featuring the Joker (Jared Leto) is all set to hit the big theatres in August.

Besides "The Killing Joke," there are three other DC titles in the Top 20: Garth Ennis' "Preacher Book One," at #8, "Batman Vs. Superman: The Greatest Battles" at #10 and Alan Moore's "Watchmen" at #17.

DC's biggest competitor, Marvel Comics, has two titles in the Top 20 currently: Mark Millar's "Civil War" at #3 and Cullen Bunn's "Deadpool Kills the Marvel Universe" at #13.

The synopsis of the "Killing Joke" animated movie reads:

"What does it take for a person to snap? How much despair for a mind to fracture? These are the twisted questions that the Joker has set out to answer, to show Gotham that even an ordinary man like Commissioner Gordon is only one bad day away from sheer insanity. Based on the acclaimed DC Comics graphic novel, witness a journey into the dark psyche of the Clown Prince of Crime. Follow his humble beginnings as a struggling comic to his fateful encounter with the Dark Knight that changed everything. Fuelled by the return of Kevin Conroy as Batman and Mark Hamill as The Joker, witness the birth of a super villain, the fortitude of a hero and the punchline that will leave you speechless."

The voice cast of "The Killing Joke" includes Kevin Conroy, Mark Hamill, Tara Strong, Ray Wise, John DiMaggio, Robin Atkin Downes, Brian George, JP Karliak, Andrew Kishino, Nolan North, Maury Sterling, Fred Tatasciore, Bruce Timm, Anna Vocino, Kari Wahlgren, and Rick Wasserman.

Directed by Sam Liu and executive produced by Bruce Timm, "The Killing Joke" has a script written by Brian Azzarello. The movie will be released on Digital HD on July 26, 2016, and Blu-ray and DVD on August 2, 2016.