By Keith Coffman
DENVER, March 14 (Reuters) - A Colorado judge overseeing the mass murder case against a gunman charged with killing 12 people in a suburban Denver movie theater has rejected several defense challenges to the state's death penalty laws and abruptly canceled hearings on the issue.
The series of written opinions issued on Friday by Arapahoe County District Court Judge Carlos Samour represented a setback and rebuke to efforts by the defense to shield James Holmes from the possibility of execution, if he is convicted.
Denying several defense motions seeking to challenge Colorado's capital punishment and sentencing laws, Samour said most of the issues raised by Holmes' lawyer were "frivolous" and had already been litigated and resolved.
"To the extent the defendant wishes to change the current state of the law in Colorado, his arguments should be directed to the legislature or the Colorado Supreme Court," Samour wrote.
Holmes, 26, has pleaded not guilty by reason of insanity to murder and attempted murder charges stemming from the 2012 shooting rampage at an Aurora, Colorado, cinema during a screening of a Batman movie "The Dark Knight Rises."
Twelve moviegoers were killed in the rampage and 70 others were injured.
Prosecutors said they intend to seek the death penalty for Holmes if he is convicted.
Public defenders for Holmes have acknowledged that the one-time neuroscience doctoral candidate was the lone gunman but that he suffers from a chronic mental illness and was experiencing a psychotic episode when he opened fire in the crowded cinema.
The California native underwent a psychiatric examination after invoking the insanity defense, but the judge ordered a second evaluation after finding the first report "incomplete and inadequate."
Samour has directed that the second evaluation focus solely on Holmes' mental state at the time of the shootings.
Under a previous ruling by the judge accepting Holmes' insanity plea, the burden is on prosecutors to convince a jury that the defendant understood the difference between right and wrong when he committed the crime.
Holmes already has been declared mentally competent to stand trial - capable of understanding the proceedings against him and to assist in his own defense.
But the trial has been postponed twice while various legal issues have been sorted out, and jury selection is now set to begin in October.
Samour said he was canceling further death-penalty hearings because the written pleadings and briefs filed by attorneys from both sides had produced an adequate record.
"While the court recognizes the seriousness of the charges filed and the nature of the sentence sought by the prosecution, it declines to hold hearings simply to indulge the parties or counsel," Samour wrote. (Reporting by Keith Coffman; Editing by Steve Gorman and Gunna Dickson)