CENTENNIAL — Defense attorneys in the Colorado theater shooting case attacked the reliability of firearms analysis Wednesday, saying it is subjective and lacks statistics to measure its accuracy.
A state crime scientist testified at a pretrial hearing that he matched bullets and shell casings found at the theater to three weapons, apparently the ones officers seized at the scene.
The defense wants firearms analysis barred from the trial, scheduled to start Dec. 8. The judge did not say when he would rule.
James Holmes pleaded not guilty by reason of insanity to charges of killing 12 people and injuring 70 in the July 20, 2012, attack at a Denver-area movie theater. Prosecutors are seeking the death penalty.
Defense lawyers have acknowledged Holmes was the shooter but continue to challenge any evidence prosecutors present.
No motive for the shootings has been revealed. Holmes' attorneys say he was in the grip of a psychotic episode at the time.
At Wednesday's hearing, Dale Higashi, a forensic scientist for the Colorado Bureau of Investigation, explained how analysts examine bullets and shell casing under a microscope to identify unique markings left by the weapons that fired them.
Questioned by defense attorney Daniel King, Higashi acknowledged that different analysts can reach different conclusions about the same evidence, and that firearms analysts cannot say what the mathematical probability of a match is, the way DNA analysts can.
Higashi said one metal fragment submitted to the laboratory was lost, prompting officials to repeat all the testing. He said the final results were verified.
When he entered the courtroom, Holmes appeared to make eye contact with his parents, who were seated in the gallery. His mother nodded at him.