Prosecutors say the suspect in the Colorado theatre shooting made threats and was banned from the University of Colorado after failing a key exam six weeks before the rampage.
They made the accusations about James Holmes in court Thursday as they tried to convince a judge to let them see records from the university, where Holmes had been a graduate student.
Holmes is accused of killing 12 people and wounding 58 others in a July 20 shooting at an Aurora theatre.
They also claim professors had urged Holmes to get into another line of work before the shooting. Attorney Karen Pearson didn't disclose where their information came from.
Defense lawyer Daniel King objected to the release of the records, calling the prosecution's request a "fishing expedition".
Holmes is a former neuroscience doctoral candidate at the University of Colorado.
Prosecutors are seeking copies of 100 pages of non-medical education records subpoenaed by prosecutors and turned over last week by the school to Arapahoe County District Judge William Sylvester.
Defense attorneys are seeking to suppress the subpoena and have asked that nobody, even Sylvester, examine the documents.
Defense attorney Tamara Brady's legal reasoning about why Holmes' educational records should be off limits is unavailable. That portion of the court file remains sealed.
Prosecutors said in court that they need the documents to gain access to a notebook reportedly containing violent descriptions of an attack.
The notebook reportedly was in a package sent to CU psychiatrist Lynne Fenton.
Defense attorneys Daniel King during court hearings said the notebook is protected by a doctor-patient relationship. King claims that Holmes is mentally ill and sought Fenton for help with that illness.
Fenton is expected to testify at a hearing August 30.
Former Denver deputy district attorney and law professor Karen Steinhauser said arguments over the records are part of both sides gearing up for a trial over Holmes' sanity.
"They know it's not a question of who did this," Steinhauser said.
"This is not a question of self-defense. They know that the only possible defense is that he was not sane at the time."
School records don't have the same legal protection as communication between a doctor and patient. But Steinhauser said prosecutors would have to tell a judge why they want them.
Steinhauser said the school records, which could include emails, might help prosecutors establish that Holmes implicitly waived his right to privacy if he talked about some of the same things he spoke to his doctor about.
The university records could also contain his school application, recommendation letters, emails between professors about their impressions of Holmes, as well his grades and progress reports on his research.
Educational records released by the University of Illinois, Urbana-Champaign, a school Holmes considered attending, contained such information including a letter of recommendation that describes Holmes as having "a great amount of intellectual and emotional maturity".
"They want those records in the hopes that it could help them build their case that these are not the actions of an insane man," Steinhauser said.