By Jeanie Stokes
The American gunman who stormed a Batman movie premier and killed 12 cinemagoers has escaped the death penalty but will likely spend the rest of his life behind bars.
A Colorado jury failed to find unanimity on execution for 27-year-old former graduate student James Holmes, obliging the judge to impose a sentence of life without parole.
Last month, the killer had been convicted on 12 counts of murder in the first degree and scores more charges including murder, attempted murder and explosives possession.
But defence counsel argued he has a mental illness and urged jurors to show clemency, an appeal apparently heeded by at least one of the panel of nine women and three men.
On each of the 12 murder counts that could have merited the death penalty, the jury said, in a statement read to the court "we do not have a unanimous final sentencing verdict on this count and ... understand the court will impose a sentence of life imprisonment without the possibility of parole."
District Judge Carlos Samour thanked the jury for their service and set August 24 to 26 as the dates for Holmes' formal sentencing.
Holmes attacked the packed premiere of The Dark Knight Rises at the Century 16 theatre in Aurora on July 20, 2012, spraying bullets into the dark auditorium.
Clad in body armour and with peculiar dyed-orange hair, he fired hundreds of rounds before police halted a spree that had left 12 people dead, including a six-year-old child.
Three years later, in July of this year he was convicted on 165 charges, the jury rejecting the defence case that he was not guilty because of his mental illness.
The prosecution argued that he should be executed through lethal injection.
"He picked the time, manner and method of their deaths. Does he deserve a life sentence for that?" District Attorney George Brauchler said in his closing arguments Thursday.
"This is about justice."
But Assistant Public Defender Tamar Brady disagreed, arguing before the jurors began their deliberations that "justice without mercy is raw vengeance".
During the guilt or innocence part of the trial, jurors heard from several of the 70 survivors who were wounded in the shootings.