Three years ago, during a midnight screening of the Batman film The Dark Knight Rises, it took James Holmes just 90 seconds to fire 76 rounds in a crowded Aurora movie theater. On Tuesday, in a courthouse just a few miles away from that Colorado city, it took Judge Carlos Samour Jr far longer than that to read out the names of the 12 people Holmes killed and the 70 he injured that night.

Some of those victims and many of their family members were in the public area on Tuesday, listening mostly in silence as Samour instructed jurors on the charges against Holmes for perpetrating the July 2012 massacre. The prosecution and defense laid out their closing arguments, before handing over Holmes’s fate to the jury. Their deliberations are scheduled to begin on Wednesday morning.

Inside the courtroom, a few family members stood and chatted with one another as they waited for closing arguments to begin. Most sat in the court’s theater seats, strangely reminiscent of those in the Century Aurora 16 cinema where the attack took place, and silently stared ahead.

Laying out gut-wrenching details in his closing arguments, from the steel-penetrating bullets used to the shots at those who tried to escape in order to scare others out of following, the district attorney, George Brauchler, methodically built the case that Holmes was guilty of first-degree murder for the 12 people he killed and attempted murder for the 70 he injured.

To do that, though, he would need to prove beyond a reasonable doubt that Holmes was not insane at the time of the rampage. (Unlike many states, Colorado places the burden of proving sanity on prosecutors.) In an attempt to show Holmes’s awareness and premeditation, Brauchler walked the jury through the defendant’s Google chat transcripts, writings, and meetings with counselors which discussed killing others. “That guy was sane beyond a reasonable doubt,” Brauchler said.

Sandy Phillips, whose daughter Jessica Ghawi was killed in the 2012 Aurora movie theatre massacre, carries a T-shirt commemorating the 12 people killed in the attack, outside the Arapahoe County district court following the day of closing arguments. Photograph: Brennan Linsley/AP

Throughout his closing remarks, not once did Brauchler mention Holmes by name, pointedly referring to the defendant each time as “this guy” or “that guy”. Every few minutes, though, he stopped discussing Holmes and instead put the name of a victim on his accompanying PowerPoint presentation, often with photos.

One of the them, Josh Nolan, sat in Courtroom 201 as Brauchler showed photos of wounds that he suffered during the shooting. Nolan wept silently, clenching a walking cane against his side. A large scar on his arm was still visible.

When Brauchler discussed one of the deceased victims, 23-year-old Micayla Medek, her grandmother Marlene Knobbe began sobbing. “I’m just glad it’s over,” she told the Guardian afterward. Her mother, Rena Medek, agreed. “Now the grieving can begin.”

Though less polished than the district attorney, public defender Dan King used his closing arguments to make a forceful case that Holmes was not guilty by reason of insanity. He told the jury to rise above the gory and emotional details of the shooting and instead focus on Holmes’s lengthy history of mental illness.

“Accept that mental illness exists,” King pleaded to the jury. “You can’t just ignore the fact that he was mentally ill.” He argued: “We don’t blame people for getting cancer,” and yet “we in this country seem to be in denial about mental illness.” Holmes “inherited the disease from his family”, King said.

All four psychiatrists who evaluated Holmes agreed that he had some form of schizophrenia. But the two court-appointed forensic psychiatrists, Jeffrey Metzner and William Reid, argued that Holmes was legally sane at the time of the attack, while two psychiatrists with the defense team, Jonathan Woodcock and Raquel Gur, disagreed.

Many of the victims’ family members were perturbed at Holmes’s insanity defense. “One million people have mental illness in this country,” Medek told the Guardian. “Not all of them kill people.”

Sandy Phillips, whose daughter Jessica Ghawi was among the 12 who were killed, agreed, arguing that mental illness wasn’t a good reason for Holmes’s actions. “I really think it’s a disservice to the mentally ill to project it that way.”

A number of the victims’ family members said they were pleased with the prosecution’s performance. “We really like them,” Medek said. “They’re really nice people.” Another standing in line to get back in the courtroom told a passing Brauchler: “You rocked it.”

After hundreds of hours of testimony and proceedings, the jury’s nine women and three men are now charged with deciding Holmes’s fate. If they vote to convict, prosecutors have said they will seek the death penalty. Colorado currently has just three individuals on death row and the state has only executed one person in the past 38 years.

Back in the courtroom, Brauchler was given the last word of the trial. He blasted Holmes’s insanity defense, arguing that his thought process was rational and his actions were premeditated.

“Sane. Sane. Sane. Guilty.” Brauchler closed, standing just feet from where the defendant sat. Holmes slowly twisted in his chair.