Centennial, Colorado (CNN) Will James Holmes face death for killing 12 people inside an Aurora, Colorado, movie theater?

That could be the next question jurors will be asked after finding Holmes guilty Thursday of first-degree murder in the July 2012 shooting.

Holmes faced two counts of first-degree murder for each of the 12 victims. The jury found him guilty on all 24 counts.

Holmes, who had pleaded not guilty by reason of insanity, showed no reaction as the verdict against him was announced. He stood at the defense table with his attorney, his hands in his pockets. He faced a total of 165 charges.

The jury also found Holmes guilty of attempted murder on all of the 140 counts against him for the 70 people wounded in the shooting. Additionally, he was found guilty of one count of possession or control of an explosive or incendiary device.

The gallery in the courtroom was full of survivors of the shooting and friends and family of the victims. Tissue boxes were underneath many of their seats. Before the reading, the mother of victim Jessica Ghawi was holding her daughter's green scarf up to her eyes while she waited to hear the verdict.

When the judge read the first guilty verdict, family members let out an audible sigh. As the verdicts continued to be read, and people waited for the specific counts relating to their loved ones, family members started reaching out to one another -- placing their hands on each others' shoulders and backs in support.

Sandy Phillips, Ghawi's mother, later cheered the verdict, saying: "We are very happy that this animal, that this monster, will never see the light of day."

Jansen Young, the girlfriend of victim Jonathan Blunk, said she felt relief as the verdict was read.

"I didn't know what I would feel when I came, but I just feel so much relief. Justice is here," she told CNN affiliate KMGH. "This is a huge step forward today."

The verdict was reached in almost 12½ hours: The jury began deliberations Wednesday morning.

A sentencing phase, which is expected to last about one month, is slated to begin next Wednesday. The same jury will deliberate during that phase. In 2013, the prosecution signaled it would seek the death penalty.

By virtue of his insanity plea , the now 27-year-old Holmes had never denied he was behind the killings. But given his mental state, his lawyers argued that he should not be found culpable.

"The evidence is clear that he could not control his thoughts, ... he could not control his actions, and he could not control his perceptions," defense attorney Dan King said during closing arguments.

King told the court psychosis had obscured Holmes' ability to think about things the way a rational person does.

"Only the mental illness caused this to happen and nothing else."

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'Hold this man accountable'

Prosecutors -- who called more than 200 witnesses to the stand, among them investigators, students who knew Holmes and his ex-girlfriend -- insisted the shooter knew well what he was doing. He acted deliberately to deliver pain and his mental issues shouldn't excuse him from paying the price, they argued.

"Look at the evidence, then hold this man accountable," Arapahoe County District Attorney George Brauchler said. "Reject this claim that he didn't know right from wrong when he murdered those people and tried to kill the others. ...

"That guy was sane beyond a reasonable doubt, and he needs to be held accountable for what he did."

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Having bought a ticket 12 days earlier, Holmes on July 19, 2012, walked into the theater No. 9 screening of "The Dark Knight Rises" like other patrons. He then walked out through a rear door, which he left propped open.

Just after midnight, some 18 minutes after the movie began, he returned wearing a ballistic helmet, a gas mask, black gloves and protective gear for his legs, throat and groin.

A tear gas canister exploded in the theater, then gunfire erupted from an AR-15 rifle, a 12-gauge shotgun and at least one .40 caliber handgun. The shooting stopped with Holmes' arrest outside the theater about seven minutes after the first 911 calls were made to police.

Photos: Colorado massacre: Mourning the victims Cynthia Davis, center, visits the roadside memorial set up for victims of the Colorado shooting massacre across the street from the Century 16 movie theater on Monday, July 30, 2012, in Aurora, Colorado. Twelve people were killed in the theater early July 20, 2012, during a screening of "The Dark Knight Rises." Suspect James Holmes was taken into custody shortly after the attack. More photos: Colorado movie theater shooting Hide Caption 1 of 52 Photos: Colorado massacre: Mourning the victims People visit the roadside memorial set up for victims of the massacre on Monday. Hide Caption 2 of 52 Photos: Colorado massacre: Mourning the victims Visitors pray around a cross at the memorial across the street from the theater on Saturday, July 28. Hide Caption 3 of 52 Photos: Colorado massacre: Mourning the victims Jeremy Blocker displays a new tattoo honoring the victims. Hide Caption 4 of 52 Photos: Colorado massacre: Mourning the victims Members of Alex Sullivan's family embrace at a memorial across the street from the Century 16 movie theater on Thursday, July 26. Hide Caption 5 of 52 Photos: Colorado massacre: Mourning the victims Hello Kitty-themed flowers are sent to shooting victim Micayla Medek's funeral Thursday in Denver. Hide Caption 6 of 52 Photos: Colorado massacre: Mourning the victims Pallbearers carry Micayla Medek's coffin during her funeral at the New Hope Baptist Church on Thursday. Hide Caption 7 of 52 Photos: Colorado massacre: Mourning the victims People visit a memorial across the street from the Century 16 movie theater on Thursday, July 26, in Aurora, Colorado. Hide Caption 8 of 52 Photos: Colorado massacre: Mourning the victims Angella Aquilis, left, and Maria Olivas mourn together at a makeshift memorial across the street from the Century 16 movie theater Wedesday, July 25. Hide Caption 9 of 52 Photos: Colorado massacre: Mourning the victims Yvonne Amaro, 9, prays for those injured and killed as she visits the memorial on Wednesday. Hide Caption 10 of 52 Photos: Colorado massacre: Mourning the victims Carrie Hensley, left, and Hailee Hensley mourn together on Wednesday. Hide Caption 11 of 52 Photos: Colorado massacre: Mourning the victims Kevin Flynn, left, Aurora Police top brass division chief, and Cmdr. Jack Daluz visit the makeshift memorial. Hide Caption 12 of 52 Photos: Colorado massacre: Mourning the victims A couple embraces as "Dark Knight Rises" star Christian Bale and his wife, Sandra Blazic, wait to place flowers at the memorial on Tuesday. Hide Caption 13 of 52 Photos: Colorado massacre: Mourning the victims Bale places flowers at the memorial while other mourners look on. Hide Caption 14 of 52 Photos: Colorado massacre: Mourning the victims Visitors pay tribute Tuesday, July 24, at the makeshift memorial. Hide Caption 15 of 52 Photos: Colorado massacre: Mourning the victims A cross stands at the makeshift memorial for victims across the street from the Century 16 theater on Tuesday. Hide Caption 16 of 52 Photos: Colorado massacre: Mourning the victims Greg Zanis of Aurora, Illinois, carries two of the 12 crosses he made for a makeshift memorial to the victims of last weekend's mass shooting at the Century 16 movie theater on Sunday, July 22. Hide Caption 17 of 52 Photos: Colorado massacre: Mourning the victims Greg Zanis writes the names of the victims of last weekend's mass shooting on the crosses before erecting them at the memorial across from the Century 16 movie theater on Sunday. Zanis, a carpenter, drove all night from Illinois to deliver the crosses. Hide Caption 18 of 52 Photos: Colorado massacre: Mourning the victims Parishioners pray during morning Mass, remembering victims of the theater shooting, at the Queen of Peace Catholic Church on Sunday. Hide Caption 19 of 52 Photos: Colorado massacre: Mourning the victims Angie Terry of Alabama prays next to a white wooden cross erected for victims. Hide Caption 20 of 52 Photos: Colorado massacre: Mourning the victims A man pauses before the crosses at the memorial near the Century 16 movie theater on Sunday. Hide Caption 21 of 52 Photos: Colorado massacre: Mourning the victims President Barack Obama embraces Colorado Gov. John Hickenlooper as Sen. Mark Udall, left, and Sen. Michael Bennet look on during a visit to the University of Colorado Hospital on Sunday. Hide Caption 22 of 52 Photos: Colorado massacre: Mourning the victims Mourners bow their heads in prayer during the vigil for the victims of the Aurora shooting. Hide Caption 23 of 52 Photos: Colorado massacre: Mourning the victims A woman is overcome with emotion during the vigil. Hide Caption 24 of 52 Photos: Colorado massacre: Mourning the victims Tiffany Garcia, right, and her 6-year-old daughter, Angelina Garcia, cry on Saturday, July 21, as they look at a memorial for the victims of Friday's shooting. Hide Caption 25 of 52 Photos: Colorado massacre: Mourning the victims People pray at a cross erected at the makeshift memorial across the street from the Century 16 theater on Saturday. Hide Caption 26 of 52 Photos: Colorado massacre: Mourning the victims Family, friends and former classmates of movie theater shooting victim A.J. Boik gather for a memorial service at Gateway High School on Saturday. Hide Caption 27 of 52 Photos: Colorado massacre: Mourning the victims Boik and his girlfriend were at the midnight showing of 'The Dark Knight Rises' when a gunman killed Boik and 11 other people. Hide Caption 28 of 52 Photos: Colorado massacre: Mourning the victims Movie theater shooting victim A.J. Boik's girlfriend, Lasamoa Croft, center, embraces his mother during the memorial service. Hide Caption 29 of 52 Photos: Colorado massacre: Mourning the victims Eman Alexander, 17, pins a ribbon on his shirt while joining family, friends and former classmates to honor shooting victim A.J. Boik. Hide Caption 30 of 52 Photos: Colorado massacre: Mourning the victims Denise Toepel of Denver sheds tears while visiting a makeshift memorial across the street from the Century 16 movie theater on Saturday, July 21. Hide Caption 31 of 52 Photos: Colorado massacre: Mourning the victims Handwritten signs decorate the makeshift memorial across from the Century 16 movie theater on Saturday. Hide Caption 32 of 52 Photos: Colorado massacre: Mourning the victims Gerald Wright, 24, relights candles that have blown out at the victims' memorial across from the movie theater. Hide Caption 33 of 52 Photos: Colorado massacre: Mourning the victims Aviation Boatswain's Mate 3rd Class Jajuan Mangual lowers the American flag on the flight deck of the aircraft carrier USS George H.W. Bush to half-mast on Saturday. One U.S. Navy sailor was killed in the shooting and another injured. Hide Caption 34 of 52 Photos: Colorado massacre: Mourning the victims Two women mourn near the theater on Saturday. Hide Caption 35 of 52 Photos: Colorado massacre: Mourning the victims Alicia Prevette, left, and Paul Stepherson attend a vigil for the victims Friday at the Century 16 movie theater. Hide Caption 36 of 52 Photos: Colorado massacre: Mourning the victims A woman lights a candle at a makeshift memorial where the victims of the massacre are mourned. Hide Caption 37 of 52 Photos: Colorado massacre: Mourning the victims Mourners hold hands at a vigil near the theater. Hide Caption 38 of 52 Photos: Colorado massacre: Mourning the victims Mourners hug as they grieve the loss of the victims. Hide Caption 39 of 52 Photos: Colorado massacre: Mourning the victims A group of teenagers stand behind a sign that reads "Strength." Hide Caption 40 of 52 Photos: Colorado massacre: Mourning the victims Dara Anderson, left, and Monique Anderson cry during a candlelight vigil across the street from the crime scene. Hide Caption 41 of 52 Photos: Colorado massacre: Mourning the victims A woman holds a lit candle at a makeshift memorial. Hide Caption 42 of 52 Photos: Colorado massacre: Mourning the victims Marietta Perkins of Denver prays for victims and their families. Hide Caption 43 of 52 Photos: Colorado massacre: Mourning the victims Lonnie Delgado, right, hugs Heaven Leek during a prayer. Hide Caption 44 of 52 Photos: Colorado massacre: Mourning the victims A mourner grieves on the curb during a memorial service. Hide Caption 45 of 52 Photos: Colorado massacre: Mourning the victims People hug during a vigil for the victims. Hide Caption 46 of 52 Photos: Colorado massacre: Mourning the victims Handwritten consolation letters lie beneath flowers at a makeshift memorial. Hide Caption 47 of 52 Photos: Colorado massacre: Mourning the victims Nathan Mendoza, left, and Melissa Clark sit on the grass during a vigil. Hide Caption 48 of 52 Photos: Colorado massacre: Mourning the victims Flags, flowers and candles make up a memorial site. Hide Caption 49 of 52 Photos: Colorado massacre: Mourning the victims Two mourners sit on the ground at a vigil. Hide Caption 50 of 52 Photos: Colorado massacre: Mourning the victims A sign prevents moviegoers from wearing masks or bringing in props to the AMC Arapahoe Crossing 16 movie theater in Aurora. Hide Caption 51 of 52 Photos: Colorado massacre: Mourning the victims A woman looks at a makeshift memorial after attending a candlelight vigil. Hide Caption 52 of 52

'Not a monster'

The shooter's parents, Robert and Arlene Holmes, were regulars in court during their son's trial. They have not talked to reporters. But they have written two open letters and published a prayer book detailing the family's internal struggle and pleading for their son's life.

James Holmes' mother struggled to hold back emotions in court Thursday. With her daughter's arm around her, Arlene Holmes blotted her eyes.

After court was adjourned, James Holmes turned around once to make eye contact with his family, which was not looking in his direction. He tried again; they were blocked from view. He didn't call out to them, and his family had already begun to file out of the courtroom.

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In a December 2014 letter published in the Denver Post , the shooter's parents said, "We have spent every moment for more than two years thinking about those who were injured, and the families and friends of the deceased who were killed, in the theater shooting in Aurora.

"We are always praying for everyone in Aurora. We wish that July 20, 2012, never happened."

Still, while they don't deny James Holmes was behind the carnage, the parents said they didn't think he should have been put on trial, much less be convicted and possibly face the death penalty, given his mental state.

"(James Holmes) is not a monster. He is a human being gripped by a severe mental illness," his parents wrote. "We believe that the death penalty is morally wrong, especially when the condemned is mentally ill."