Friday's verdict came after the jurors in the case, heard in the town of Centennial, outside of Denver, had deliberated for more than six hours over two days. The life sentence came as the nine women and three men on the jury failed to reach a unanimous decision to sentence the 27-year-old Holmes to death on any of the 24 counts against him.

Reading out the verdict, Arapahoe County District Court Judge Carlos Samour explained that due to the jurors' inability to agree unanimously that Holmes should be executed by lethal injection, the court had sentenced him to life in prison with no chance of parole.

Holmes, who had been convicted on all of the charges last month, showed no reaction as his sentence was read out, staring straight head with his hands in his pockets.

In his final argument, District Attorney George Brauchler has called on the jurors to sentence Holmes to death, saying this was the only appropriate appropriate sentence for Holmes. However, his defense attorney, Tamara Brady urged them to have mercy on her client, saying his schizophrenia and psychotic delusions had driven him to his actions.

Midnight movie screening

The killings came during a midnight screening of the Batman film "The Dark Knight Rises" in Aurora, Colorado on July 20, 2012. Seventy people were also injured in the shooting.

During the trial which began in April and lasted for 60 days, there was never any doubt that Holmes was the killer, as following the shootings, he had surrendered to police, while clad from head to toe in combat gear.

Prosecutors argued that Holmes, a former neuroscience graduate student had intended to kill all of the around 400 people in the cinema, but that he failed to do so in part because a drum magazine that he had bought to boost his firepower jammed.

Dozens of survivors who were wounded in the shooting testified during the trial.

Proceedings could have been concluded much earlier, as Holmes had offered two years ago to plead guilty if the court would refrain from sentencing him to death. However, this offer was rejected by the prosecution.

pfd/bw (Reuters, dpa, AP)