James Holmes will undergo a second court-ordered psychiatric evaluation, after the judge overseeing the Aurora movie theater murder case ruled that the first exam was “incomplete and inadequate.”

In an order issued Wednesday, Arapahoe County District Court Judge Carlos Samour agreed with prosecutors that the psychiatrist who performed the first exam, Dr. Jeffrey Metzner, didn’t sufficiently explain how he reached his conclusions about Holmes’ sanity on the night of the shooting.

“[A]lthough Dr. Metzner collected and documented a lot of factual information as part of his examination, he offered little rationale for some of his opinions and findings,” Samour wrote. “… The bases for Dr. Metzner’s opinion regarding the issue of sanity are just as important to the truth-finding process as the opinion itself.”

However, Samour rejected the prosecution’s request that the new evaluation be conducted by doctors hired by the prosecution. Instead, Samour ordered officials at the Colorado Mental Health Institute, who appointed Metzner to conduct the first evaluation, to pick a new independent doctor for the second evaluation.

The ruling will significantly delay the case’s trial, which was already on hold while Samour considered the prosecution’s request. Samour set a deadline for the report of the second evaluation to be completed by July 11, nearly two years after the attack.

In a separate order issued Wednesday, Samour wrote that he hopes to set a new trial date during a hearing next week.

Holmes has pleaded not guilty by reason of insanity to charges that he murdered 12 people and tried to kill many more inside the Century Aurora 16 movie theater on July 20, 2012. As a consequence of the plea, Samour ordered Holmes to undergo a psychiatric exam by an independent doctor — an effort to create a level playing field for prosecutors and defense attorneys to debate Holmes’ sanity. Such examinations are crucial in insanity-defense cases, since juries almost always side with the findings of the report.

The results of Metzner’s exam have not been revealed, other than that Metzner found Holmes mentally well enough currently to stand trial. But Samour revealed in his order Wednesday that prosecutors challenged Metzner’s conclusions only about Holmes’ sanity at the time of the crime.

While that makes it appear that Metzner’s report was favorable to the defense, Denver attorney Karen Steinhauser said it may not ultimately be useful to the defense at trial since prosecutors were able to raise doubts about it.

“So it raises the question of how valuable Dr. Metzner’s report will end up being,” she said.

John Ingold: 303-954-1068, jingold@denverpost.com or twitter.com/john_ingold