BATMAN Shooter” suspect JAMES HOLMES has grown a bushy new beard as a symbol of his newfound faith – Islam.

And The ENQUIRER has learned the accused murderer – now awaiting trial for a bloody shooting spree at an Aurora, Colo., movie theater last July – has turned to the religion in a twisted attempt to condone the horrific slaughter.

“Holmes has been scrambling to justify hurting all of those innocent people, and he’s convinced that converting to Islam will ultimately be his saving grace,” a prison source told The ENQUIRER. “He’s gone off the deep end. He has brainwashed himself into believing he was on his own personal jihad and that his victims were infidels.

“Because Holmes is under lockdown and has nothing but time on his hands, he spends hours upon hours each day alone in a cell, reading and studying the Holy Qur’an.”

He has also started performing the ritual Islamic “salat” prayer five times a day and is trying to follow a strict Islamic diet, the source added.

ON March 12, a judge in Centennial, Colo., entered a “not guilty” plea for Holmes, who’s facing 166 counts of first-degree murder and attempted murder in the July 20 massacre. The mass shooting, during a midnight showing of “The Dark Knight Rises,” left 12 people dead and 58 wounded.

The source says other Muslim inmates at the Arapahoe County Detention Facility are furious that Holmes is trying to use their faith to validate his violent rampage.

“None of them condone forms of terrorism or extremism,” noted the source. “And they don’t want their religion to be connected to that awful shooting.”