In Colorado, the jury convicted mass shooter James Holmes with 12 counts of first-degree murder and multiple attempted murder charges, which happened on July 20, 2012 inside a movie theater during the screening of the Batman movie, "The Dark Knight Rises" in Aurora.

The Wall Street Journal reports Holmes did not show any reaction as Arapahoe Country District Chief Judge Carlos Samour, Jr. was reading the verdict on Thursday, after his defense lawyers argued that the convicted was battling with mental illness at the time of his attack.

"The mental illness is the sole reason this crime took place," defense lawyer Daniel King told the jurors. University of Pennsylvania medical school's neuropsychiatry program director, Raquel Gur, testified that the suspect was suffering schizophrenia during the mass shooting.

Public defenders added Holmes' insanity ran in his family and that he was not aware killing was morally wrong at that moment.

Witnesses recalled at the trial how Holmes walked in shadows after the blockbuster movie started, and bombed the theater with tear gas just before he started firing shots.

12 people were dead and many got injured while hiding under their seats in a night of real-life terror.

According to prosecutors, Holmes attack was plotted and was motivated by anger and social anxiety, which rooted back during his struggles at school.

Arapahoe County District Attorney George Brauchler told the jury Holmes committed the crime "to make himself better."

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

The jury composed of 9 women and 3 men rejected the arguments raised by Holmes' defense lawyer, who challenged them to avoid making a decision based on emotions and retribution.

The former graduate school student at University of Colorado may face life imprisonment without parole or even death sentence when punishment will be announced.