A US jury found James Holmes guilty on Friday for all 24 counts of first-degree murder in the shooting incident at a movie theatre in Aurora, Colorado, making the gunman eligible for the death penalty.
Holmes faced two counts of first-degree murder for each of the 12 victims.
The jury reached its decision after long deliberations and the decision was taken almost three years after the incident took place.
The jury’s verdict was revealed by Arapahoe County District Chief Judge Carlos Samour Jr. at 4:15pm local time.
As the judge read through count after count of charges of first-degree murder and attempt to commit murder in the first degree, the former neuroscience graduate student stood still, staring in front of him without any reaction.
Holmes pleaded not guilty by reason of insanity and to support his claim, the defence hired two other psychiatrists who found that Holmes is delusional and schizophrenic and cannot be held accountable for the massacre.
Two psychiatrists appointed by the court, however, testified that Holmes was mentally ill, but that the neuroscience graduate student was sane when he committed the crime.
Jurors rejected the defence’s claim of insanity when making their decisions.
The mass shooting took place during a screening of “The Dark Night Rises” in Aurora, a city in Colorado, the US, on July 20, 2012 killing 12 people and wounding another 70.
The ages of victims killed range from a 6-year-old to a father of four at the age of 51.
Fifty-eight people were wounded by gunfire and 12 others suffered from other injuries while trying to escape the theatre at the time of the mass shooting.
Whether Holmes should be sentenced to death will be decided by the same jury panel on Wednesday.