Washington, Aug 26 (IANS): Academic failures and insults may have caused accused James Holmes to booby trap his apartment with explosives and plan the shootings during the "Batman" movie screening, US prosecutors have said.

In new information revealed in court in Aurora, Colorado, prosecutors said the 24-year-old Holmes had failed his June 6 oral exams.

He was told by a professor to "try another business".

Holmes then "made threats", which caused him to be banned from the University of Colorado, where he was enrolled as a neuroscience Ph.D candidate.

Holmes is being held without bond in Centennial, Colorado after the July 20 shooting, which left 12 dead and 58 injured. He faces the death penalty if found sane.

Holmes' sanity has become the centrepiece of his trial, and his communication with university psychiatrist Lynne Fenton just prior to the shootings is a clue to determining his condition.

Prosecutors are asking the court for Holmes' academic records and a notebook he sent Fenton before the shootings, which may reveal he planned the massacre and was sane.

"It's the job of the defence to keep any information out that might prove he was guilty," pointed out Denver criminal lawyer V. Iyer.

Defence lawyers are asking District Court Judge William Sylvester to deny the request on the grounds the information is protected by doctor-patient confidentiality, as mandated by the Health Insurance Portability and Accountability Act of 1996.

If the notebook reveals Holmes planned the attack, the evidence may be used against him.

"Only if he is proved insane can those psychiatric records be released," Iyer said. "Under the act, all communication with his psychiatrist is privileged and cannot be used against him."

But in court, the prosecution's chief deputy attorney Karen Pearson insisted all records be released.

"What was happening in the defendant's academic life was extremely relevant," she said.

"He didn't do well on his labs, he failed his oral boards on June 6, at the same time he was buying body armour, weapons and ammunition."

Holmes was defended by Daniel King, who accused the prosecution of inappropriate conduct by already obtaining undisclosed information about Holmes' academic standing.

"We take an oath to uphold the Constitution of the United States, and that means the defendant has the right to a fair trial, even if it's a heinous crime," Iyer said. "It's the American legal system. Holmes has rights."

King told the court that "nothing in those documents will reveal intent", and "they already have what they say they are apparently seeking".

"Was he insane at the time of the shooting? That's all that matters," Iyer said, "not if a notebook he had gave references to what he might do".