The few journalists allowed to attend the hearing will be watching to see if there is a repeat of the 24-year-old's bizarre behavior during his first court appearance a week ago.
Under a mop of brightly-dyed orange and red hair, he stared out wild-eyed at times and appeared almost dazed and sleepy at others, ostensibly unable to keep up with the proceedings.
Prosecutors have reportedly been battling defense lawyers over a package Holmes sent to his psychiatrist at the University of Colorado portending the midnight massacre on July 20 at a cinema in Aurora, near Denver.
Holmes gained access to the movie theater via a fire exit shortly after the start of the latest Batman film, "The Dark Knight Rises," and threw two canisters of noxious gas into the auditorium, witnesses and police said.
After firing into the air with a pump-action shotgun, the former graduate neuroscience student allegedly began shooting people at random with a military-style assault rifle capable of firing 50 to 60 rounds a minute.
Twelve people died, including six-year-old Veronica Moser-Sullivan. The girl's mother, among 58 moviegoers wounded, is in critical condition after being shot in the neck and stomach and has since lost her unborn child.
Holmes could be charged with up to two counts of first-degree murder for each of the 12 people he allegedly killed. He could also face attempted murder charges for everyone who was in the cinema, not just those shot.
Prosecutors have said it will be several weeks before a decision is made on whether or not to seek the death penalty. Only one person has been executed in Colorado since capital punishment was reinstated in 1976.
Attorneys for Holmes disclosed on Friday that he had been a patient of University of Colorado psychiatrist Lynne Fenton as they sought to gain access to a package he had mailed to her prior to the massacre.
According to ABC News, his lawyers are accusing prosecutors of leaking the existence of the package - reportedly containing macabre plans, including drawings of a stick-figure gunman mowing down victims - to the media.
"The government's disclosure of this confidential and privileged information has placed Mr Holmes' constitutional rights to due process and a fair trial by an impartial jury in serious jeopardy," his attorneys wrote.
The package was found in the university mailroom on the Monday after the shooting. There are conflicting reports about when it was sent so it is not clear if its discovery earlier could have prevented the atrocity.
There has been speculation that stress over failing a key exam may have been the trigger that caused Holmes, a promising neuroscience student who had won a prestigious government grant, to become unhinged.
ABC News' affiliate in Denver, KMGH-TV, reported that Holmes purchased a high-powered rival on June 7, hours after taking a key oral test. Three days later, he dropped out of his neuroscience program.
Soul-searching has been intense since the tragedy, but despite the staggering number of mass shootings in the United States there is no political will to address the toxic gun law issue, especially four months out from a presidential election.
US Senators Frank Lautenberg of New Jersey and Congresswoman Carolyn McCarthy of New York, both Democrats, are expected to announce new legislation on Monday that they plan to introduced this week.
The bill aims "to make the online and mail-order sale of ammunition safer for law-abiding Americans who are sick and tired of the ease with which criminals can now anonymously stockpile for mass murder," they said.
Holmes had stocked up on more than 6,000 rounds of ammunition over the Internet after stocking up on four weapons in local gun shops.
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