James Holmes: Parents pf Dark Knight shooter emerge from hiding to support him in court Today marked the first time his parents have shown up Have been in relative hiding since the horrific killing spree Defense said they could not enter a plea so judge entered for him Can be changed at a later date The judge in the deadly Colorado movie theater shooting case entered a not guilty plea on behalf of James Holmes on Tuesday, which marked the first time his parents appeared in court to support him. Robert and Arlene Holmes have been in relative hiding since their son allegedly opened fire on a movie theater in Colorado. They were stony faced at the hearing today and refused to speak to reporters. If Holmes is convicted, he could be executed or spend the rest of his life in prison. Judge William Sylvester said Holmes, 25, can change his plea to not guilty by reason of insanity later, if he chooses. Such a change could be the only way Holmes could avoid life in prison or execution. Prosecutors for their part have not said yet whether they will pursue the death penalty, announcing on Tuesday that they will make their decision known on April 1. No plea: Accused Aurora theater shooting suspect James Holmes listens with public defender Tamara Brady at his arraignment in Centennial, Colorado on March 12 Support: Robert Holmes, right, and his wife Arlene, parents of alleged shooter James Holmes, listen to arguments during their son's plea hearing at Arapahoe District Courthouse Blank: Holmes sat silently through Tuesday's proceedings. He wore a red jail jumpsuit and sported a thick, bushy beard and unkempt dark brown hair Coming out: James Holmes' parents Robert and Arlene Holmes arrive at district court for the arraignment of their son Aurora theater shooting suspect James Holmes As he has done in past hearings, Holmes sat silently through Tuesday's proceedings. He wore a red jail jumpsuit and sported a thick, bushy beard and unkempt dark brown hair. When he walked into the courtroom, he looked at his parents, James and Arlene Holmes. They sat silently at the front of the room and left without comment after the hearing. Holmes is charged with multiple counts of murder and attempted murder in the July 20 attack at a suburban Denver movie theater that killed 12 people and injured 70. In the nearly eight months since Holmes first shuffled into court with vacant eyes and reddish-orange hair, neither he nor his lawyers have said much about how he would plead. Holmes' lawyers repeatedly raised questions about his mental health, including a recent revelation that he was held in a psychiatric ward for several days last fall, often in restraints, because he was considered a danger to himself. That raised the possibility that they could end up entering a plea of not guilty by reason of insanity at the hearing on Tuesday. Holmes' lawyers, however, said they were not ready to enter a plea. The plea carries risk, however. Prosecutors would gain access to Holmes' mental health records, which could help their case if the evidence of insanity is weak. If Holmes does plead insanity, the proceedings would be prolonged further while he is evaluated by state mental health officials. With the judge entering the plea, prosecutors would not have access to Holmes' health records. Judge: William Blair Sylvester speaks during James Holmes' arraignment, where he entered a not guilty plea for Holmes Stalling: The former graduate student's defense team said he was not ready to enter a plea so the judge entered one for him Guard: James Holmes is accused of going on a shooting spree almost eight months ago that killed 12 moviegoers and injured another 60 Face off: Lead defense attorney Daniel King, left, and members of the Arapahoe County prosecution team, right, arrive for the plea hearing arrive at district court for the arraignment of James Holmes After effects: Family members and victims arrive at district court for the arraignment of James Holmes, Aurora theater shooting suspect, in Centennial During the hearing, defense attorney Daniel King said he could not advise Holmes on what plea to enter. He said the defense wasn't ready despite previous delays - prompting prosecutors to object. Sylvester asked King when Holmes might be ready to enter a plea. We could be ready by May 1. It may be June 1,' King said. So how am I supposed to make an informed decision? Sylvester said before entering the not guilty plea. He said they defense can always petition to change the plea to not guilty by reason of insanity. At one point, in saying they weren't ready to enter a plea, King said: 'We have ongoing work scheduled. We're doing the best that we can.' But he said he couldn't reveal what the work was or say when it would be finished. If a jury agrees he was insane, Holmes would be committed indefinitely to a state mental hospital. There would be a remote and unlikely chance he could be freed one day if doctors find his sanity has been restored. Prosecutors laid out a case that Holmes methodically planned the shooting for months, amassing an arsenal and elaborately booby-trapping his apartment to kill anyone who tried to enter. On the night of the attack, they say, he donned a police-style helmet, gas mask and body armor, tossed a gas canister into the seats and then opened fire. Holmes is charged with 166 counts, mostly murder and attempted murder, in the assault on moviegoers at a midnight showing of The Dark Knight Rises in Aurora. The judge set August 5 for the start of the trial. Prosecutors and defense attorneys declined comment. Subject: Suspect James Holmes could be required to submit to a 'narcoanalytic interview' as part of an evaluation to determine if he was legally insane at the time of the July 20 shootings Suspect: Holmes is accused of killing 12 people at an Aurora movie theater on July 20 The same judge ruled yesterday that Holmes can be given "truth serum" for his medical examinations if he pleads not guilty by reason of insanity. If he enters that plea, he could be required to submit to the 'narcoanalytic interview' as part of an evaluation to determine if he was legally insane at the time of the July 20 shootings. Sylvester said Holmes also could be given a polygraph examination as part of his evaluation. After reading a draft of the advisory, Holmes' lawyers objected, saying a narcoanalytic interview and a polygraph would violate their client's rights. In the final version of the advisory, Sylvester said he had incorporated some suggestions from the defense and the prosecution, but he did not address the defense objections to a narcoanalytic interview and polygraph. Karen Steinhauser, a former prosecutor who is a law professor at the University of Denver and a defense attorney, said she could not find any case law about use of the narcoanalytic interview. 'It comes up so rarely,' she said, adding she knows nothing about it. She noted the technique is clearly allowed by Colorado law. That hospitalization, defense lawyers noted, was separate from an earlier incident where Holmes was treated at a hospital for injuries 'that resulted from potential self-inflicted head injuries in his cell.' The motion said the sheriff's office refused to give the video to prosecutors or defense attorneys at the direction of Arapahoe County Sheriff Grayson Robinson. Robinson told Reuters on Friday night that he had released a 'relevant video to both sides,' but citing a gag order imposed by the judge in the case, declined to comment on its contents. Robinson said his office had been 'straightforward and cooperative' in the case, and that he would not release the hospital video because it was taken outside his jurisdiction. In the dock: Colorado shooter James Holmes appears confused while making his first court appearance at the Arapahoe County on July 23 Memorial: Tributes are left for victims near the scene of the tragedy in Colorado that claimed 12 lives 'I told them (attorneys) that I didn't have the authority to give them that video because it was taken in Denver and they'd have to go through them,' he said. In rejecting the defense motion to declare Colorado's insanity defense law unconstitutional, Sylvester said defense lawyers had raised the issue prematurely since Holmes had yet to enter a plea, and prosecutors had not indicated whether they would seek the death penalty. Lawyers for Holmes last week challenged the constitutionality of a Colorado statute that requires a defendant who raises an insanity defense to submit to examinations by court-appointed psychiatrists. Defense lawyers argued that the law, which would compel Holmes to provide potentially damaging information that could be used against him at trial, or at sentencing should he be convicted, violated his Fifth Amendment guarantee of protection against self-incrimination. Paying respects: People visit a memorial for the victims in the shooting across the street from the Century 16 movie theater in Aurora two days after the shootings