A judge entered a plea of not guilty for Colorado shooter James Holmes on Tuesday.

The former neuroscience student was charged with killing 12 people and wounding several others in an Aurora movie theater on July 20, 2012.

In the days leading up to Tuesday's hearing Judge William R. Sylvester laid out the groundwork for Holmes to plea not guilty by reason of insanity, explaining the mental examinations and court-ordered interviews that would come from the respective plea.

However, Holmes' lawyers informed the court on Tuesday that they weren't ready to enter a plea as of yet and that they weren't sure when they might be ready to do so. Clearly growing impatient, Judge Sylvester denied the defense team's request for additional time and entered a plea of not guilty for Holmes.

Holmes, 25, was arrested moments after the horrific massacre that took place at a midnight screening of The Dark Knight Rises. Prosecutors have already given hours of both testimony and documentary evidence that Holmes was the shooter who snuck out of the theater, armed himself inside the parking lot and then re-entered the building through an emergency exit to begin his killing spree.

Although Holmes can still change his plea, the prosecution argued that they would fight such a move, according to The New York Times.

"As far as we're concerned, they are entering a plea of not guilty, and what they have done to this point is not sufficient to enter a plea of not guilty by reason of insanity," Karen Pearson, assistant district attorney for Arapahoe County, said in the courtroom.

The prosecution will also look to seek the death penalty against Holmes at an April 1 hearing.

The judge scheduled a four-week trial for the month of August. Given that there have been several delays in the case so far, the date reportedly may not hold.