A judge ruled Thursday that there is indeed sufficient evidence for Colorado shooting suspect James Holmes to face trial amid charges for killed 12 people and injured 70 others at an Aurora, Colo., movie theater this past summer.

Judge William Sylvester stated that prosecutors will move forward with the 166 counts of felony, which includes murder and attempted murder, after establishing probable cause. Sylvester's decision followed a three-day hearing earlier in the week where prosecutors laid out their case against the 25-year-old suspected shooter.

Holmes is scheduled to be arraigned on Friday; however, the suspect's defense attorneys filed paperwork on Thursday afternoon stating that their client wasn't ready to enter a plea. The defense team is more than likely to request a delay in the arraignment but didn't elaborate on the reason why.

Both police and federal agents testified in court that Holmes spent weeks preparing guns and ammunition, as well as manipulating explosives to booby-trap his apartment. They also said the suspect scouted the movie theater before he began shooting in front of hundreds of moviegoers on July 20, 2012.

The police gave a description of the horrific scene that took place inside the theater where 12 individuals were killed in front of their families and friends while others were wounded during a showing of "The Dark Knight Rises."

Holmes' lawyers cross-examined a couple of people called upon by prosecutors during the hearing, but didn't summon any witnesses. The defense team continues to raise the issue of the suspect's insanity, which many agree is his only chance of avoiding the death penalty.

CBS News noted that defense attorney Daniel King asked one of the witnesses the following question:

"You're aware that people can be found not guilty on the grounds of insanity?"

Tom Teves, the father of one of the late victims Alex Teves, stated that he'd prefer to see Holmes plead guilty to murder in the first-degree, which would speed up the trial and eliminate the insanity defense.

"Don't pretend he's crazy. He's not crazy. He's no more crazy than you and I," Teves stated.

If Holmes is found not guilty by reason of insanity, he could be released from prison someday if he's considered recovered.