James Holmes Hearing: Judge Orders Trial, But Insanity Debate Begins Photo by Arapahoe County Sheriff's Office via Getty Images In this photo provided by the Arapahoe County Sheriff's Office, James Holmes poses for a booking photo September 20, 2012 in Centennial, Colorado. A Colorado judge has ordered accused mass killer James Eagan Holmes to stand trial for his July 2012 theater rampage in Aurora, Colo. - but the wheels of justice, now beginning to turn, will move slowly. On Thursday, Arapahoe County Judge William Sylvester ruled that Holmes will face a jury on 166 counts of murder, attempted murder and other crimes, in an attack that killed 12 people and wounded 58 at a July 20 midnight screening of The Dark Knight Rises. But less than a day later, Sylvester postponed Holmes" arraignment until March 12, in order to give the prosecution and defense enough time to properly prepare for the case; the judge is expected to hand down formal charges on Friday. MORE: James Holmes Hearing: Prosecution Finishes, No Defense Argument; Judge Expected to Decide on Trial Friday Angry family members protested inside the courtroom while prosecutors argued they were ready to proceed with the arraignment immediately. The delay gives Holmes" lawyers more time to prepare what will likely be an insanity plea and defense. If so the high-profile trial, which some are comparing to that of Tuscon, Ariz., shooter Jared Lee Loughner, will bring debates over the definition of criminal insanity into play. Any eventual jury in this case will have to decide if Holmes was in his right mind as the tragedy unfolded, and if his actions - which included the use of a small arsenal of weapons and explosives - were calculated and premeditated. "In this case it's clear that the prosecution has a very heavy burden," says Barry Slotnick, the New York defense attorney who represented the so-called "Subway Vigilante" Bernhard Goetz in a famous 1986 shooting trial. The jury is going to be told by the defense that he had no understanding of the nature of his acts and that he was absolutely beyond being a reasonable human being. MORE: James Holmes Hearing: FBI Expert Gives Details on Aurora Shooter's Booby-Trapped Apartment The death penalty has been discussed in the Aurora case ever since Holmes" arrest, but prosecutors have not said whether or not they will pursue it, citing a number of factors including taking into account the feelings of victims" families. Executions are legal in Colorado, though rare; only one person has been put to death since the state reesstablished capital punishment in 1976. Slotnick said that prosecutors could possibly opt against pursuing execution and instead try to get a life sentence rather than risk the defense winning on an insanity plea. However, an insanity plea might be difficult to defend as well. No mass murder case in recent history has been successfully defended on such a plea, says Michael Perlin, director of the Mental Disability Law Program at New York Law School. What is important is whether Holmes is competent - and can remain competent - to undergo a trial. "It has nothing to do with guilt or innocence, it has to do with whether he can participate," said Perlin, noting that Colorado law states that a defendant must be found competent before he can even enter an insanity plea. "If you plead insanity, you have conceded that you have done the act, but "I did it because I was defending the Klingon Empire" or something of that nature." The case now becomes more complex as both sides take the next two months to prepare for an arraignment. Either the prosecutors or defense lawyers may argue to the judge that Holmes is not mentally capable of understanding his circumstances and cannot help his own defense. In that instance, Sylvester could order a mental evaluation and ultimately rule that Holmes is, in fact, incompetent to stand trial. If the judge finds that Holmes can face a jury, however, then he is expected to enter a plea of guilty, not guilty or no contest at his March arraignment. Subsequent proceedings - including picking a jury to hear the case - could, like Loughner's, take months or even years to play out, particularly if the prosecution decides to pursue the death penalty. Either way, James Eagan Holmes likely won't walk free again regardless of the verdict. Even if he is found to be not guilty by reason of mentally illness, he will almost certainly be institutionalized. "The fact of the matter is that if he's acquitted of murder by reason of insanity, it doesn't mean he goes home," Slotnick says. It means he goes into an institution.