The first week of testimony in the Aurora, Colo., theater rampage trial underscored the full horror of the 2012 attack that left 12 people dead and 70 wounded.
Burly first responders in uniform cried as they related the chaos and the carnage. Victims spoke of searing pain from bullets tearing through their flesh, of looking down and seeing their legs shattered, of viewing friends' corpses splayed on the bloody theater floor.
Week two has been more about the real challenge facing prosecutors — proving
Holmes has acknowledged planning and carrying out the attack, but has pleaded not guilty by reason of insanity to 166 charges, including first-degree murder. His trial at the Arapahoe County Justice Center in Centennial is expected to last five months.
How is Colorado's criminal code different from California's when it comes to an insanity defense?
The definition of insanity differs from state to state, and four states do not allow an insanity defense at all: Idaho, Kansas, Montana and Utah. Colorado's definition is similar to California's, but the opposite side bears the burden of proof.
In Colorado and a few other states, the prosecution must prove the defendant was sane when the crime was committed.
In California, as in most states and in federal court, the defense must prove that the accused was insane.
Which side does that benefit?
Craig Silverman, a former Denver chief deputy district attorney, argues that "the prosecution of this guy would be much easier in California, because the burden of proof is on the defendant there."
In Colorado, the prosecution must prove beyond a reasonable doubt that Holmes did not suffer "from a mental disease or defect that rendered him incapable of distinguishing from right and wrong," Silverman said. "And that's a big hurdle for the prosecution in a case like this, with quite a bit of bizarre conduct involved."
How is this showing up in court?
During opening statements, Arapahoe County Dist. Atty. George H. Brauchler went to great lengths to lay out the months before the attack, which he said Holmes spent meticulously planning. He described how Holmes bought guns and ammunition slowly over the Internet and in person and cased the Century 16 theater.
On Monday, the prosecution called Theodore Maples Jr., who volunteered at the Byers Canyon Rifle Range outside Denver in 2012 and saw Holmes practice shooting twice before the rampage.
"He was on the pistol range, and he moved later to the shotgun range," Maples testified. "The only thing I remember is the orange red hair that really stood out."
On Thursday, the prosecution put into evidence supplies that Holmes had carefully amassed. They had been collected from the rampage scene by FBI Special Agent Nick Vanicelli, who described them from the witness stand one by one: gas masks, a military-style ballistic helmet with orange hairs caught in the internal webbing, handcuffs, a Smith & Wesson "Extreme Ops" folding knife, rifle magazines filled with ammunition, and the guns Holmes had used to kill his victims.
How did jurors, who can write down questions for the judge to ask witnesses, react to testimony about Holmes' mental state?
On Tuesday and Wednesday, the prosecution called three professors with whom Holmes had worked as a graduate student in the University of Colorado-Denver's neuroscience program. They described Holmes as awkward, extremely talented in some areas but deficient in others.
At the end of each man's testimony, the jury asked some version of the same question: "Throughout your time interacting with the defendant, did he ever seem disconnected from reality?"
All of the professors seemed to agree with assistant professor Achim Klug, who was most emphatic when he testified Wednesday. "The answer is clearly no," he said.
What is the most persuasive evidence so far about Holmes' sanity, his ability to tell right from wrong?
Silverman points to a videotape played Monday of Holmes being questioned by detectives hours after the shooting. Holmes told the officers that he had seen signs in the Aurora police station for the crimes against children and victims services units.
And he asked: "There weren't any children hurt, were there?"
Silverman said that could bode ill for the defense.
"If a person were in the middle of a florid hallucination, it's doubtful that he would have taken note of that sign or shown the sense of right versus wrong to ask that question," Silverman said. "That degree of humanity may cost him his life."