The new claims against Holmes emerged as part of efforts to convince a judge to allow the prosecution access to 100 pages of education records subpoenaed from the University of Colorado, Denver, where he had been a neuroscience doctoral candidate.
The prosecutors' account presents a sharply different picture of Holmes' exit from the one provided by university officials in the days after the shooting. And a school spokeswoman said after the hearing that Holmes had not been banned.
Holmes is accused of killing 12 people and wounding 58 others in the July 20 shooting during a midnight showing of the latest Batman film. He has not issued a plea in the case and remains held without bail.
Chief Deputy District Attorney Karen Pearson did not elaborate on the nature of the threats during the hearing, nor did she disclose where the information came from.
The university turned over the documents last week, but Holmes' US lawyers moved to keep them sealed.
Pearson also told Judge William Sylvester that professors had urged Holmes to get into another profession and said his lab work had been deteriorating.
Defense lawyer Daniel King objected to the release of the records, calling the prosecution's request a "fishing expedition that needs to be stopped."
University spokeswoman Jacque Montgomery, who did not go to the court hearing, disputed the prosecution's characterisation, but said Holmes' access to restricted areas was cancelled because he left his graduate programme in June.
Prosecutors are seeking Holmes' university application, his grades, course schedules, emails concerning Holmes, and anything concerning his termination or withdrawal from the school.
"What's going in the defendant's life at the time is extremely relevant to this case," Ms Pearson said.
Holmes appeared more engaged in the hearing than previous court appearances. His walk was more deliberate when he came in courtroom. Rather than staring blankly ahead, he looked at the judge for most of the hearing.
Before a gag order was issued, the university said that campus police had no records on Holmes and that the student lost access to the school because he withdrew from the programme, not because of threats.
University officials also said Holmes lost access to university premises after his June 10 withdrawal because his student access card was shut off, rather than for threats or any other safety reason.
The university also said in writing that there were no documents related to the decision to bar Holmes from the campus.
Prosecutors say they need the university documents to gain access to a notebook reportedly containing violent descriptions of an attack. The notebook reportedly was in a package sent to university psychiatrist Lynne Fenton.
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 Aug 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," Ms Steinhauser said. "This is not a question of self-defence. They know that the only possible defence 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.
Ms 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," Ms Steinhauser said.
Edited By Cen Fox Post Team
