A Colorado judge entered a not guilty plea on behalf of accused Aurora theater shooter James Holmes, who sported a thick beard and longer hair as he sat silently throughout Tuesday’s court appearance.

Holmes, 25, pleaded not guilty during his arraignment in Colorado's Arapahoe County District Court. His lawyers plan to use an insanity defense against charges he killed 12 people and wounded 58 others during the opening-night screening of “The Dark Knight Rises” at the Century 16 multiplex in Aurora, Colo., in June.

The accused Colorado shooter’s appearance has gone through a series of changes since he was arrested.

During his first court appearance, Holmes had dyed orange hair that he allegedly styled to look like the Joker from the “Batman” films.

In the alleged shooter’s September mugshot, Holmes had a crew cut and a light beard.

Holmes’ hair has grown out considerably since then. His beard is also fuller.

New York magazine used snark to refer to the new look in a post titled “James Holmes’s Crazy New Beard Is Not Doing Him Any Favors.”

The accused Aurora shooter’s lawyers said they were not ready to enter a plea during Tuesday’s arraignment, but Arapahoe County District Judge William Sylvester said the defense is taking too long to decide on a plea. So he entered a not guilty plea on Holmes’ behalf.

“This matter has been pending since July 2012," Sylvester said, according to Reuters, referring to the arraignment. "I acquiesced to the defense and put off the date as long as we could."

The judge also scheduled Holmes’ trial for Aug. 5 and expected the case to take four weeks.

Holmes was silent during the court appearance but was described by CBS News as “alert” and “alternately appearing to look at the judge and stare into space.”

Marcus Weaver, one of the shooting victims, said he appreciated that the judge is moving the case forward, tweeted Denver Post reporter Sadie Gurman.

"Seeing [Holmes] in the courtroom today, he is human just like we all are; he does deserve a fair trial,” Weaver, who was shot in the arm, said. "There isn't a second that goes by that we don't feel the sting of his actions. Justice will be served in the end."

Holmes’ attorneys can still decide to enter a not guilty by reason of insanity plea, but the judge would have to sign off on the plea, CNN reported.

In order for such a defense to be successful, his lawyers will have to argue that he did not know the difference between right and wrong when he committed the killings.

Prosecutors claim there is sufficient evidence to dispute that Holmes was insane. They said there is evidence that Holmes bought guns and ammunition online and rigged his apartment with explosives that were triggered to go off when authorities arrived. Police were able to disarm the devices.