The suspected Batman movie premiere gunman was seeing a university psychiatrist specializing in schizophrenia before the shooting that killed 12, court documents showed Friday.
James Holmes sent a notebook to Lynne Fenton, who teaches at the University of Colorado's medical school and heads student mental services there, that included details and drawings depicting his planned mass killing, according to reports.
It was unclear when the package reached the school, and officials remained tight-lipped due to a gag order imposed by the judge overseeing the case.
But the judge unsealed a defense motion to order the government to grant access to the "package from Mr Holmes addressed to Dr Lynne Fenton."
The motion also said Holmes's constitutional rights had been violated by the "breach of confidentiality and privilege."
In a preview of likely battles to come, the defense lawyers also argued that the contents of the package should not be used as evidence because "Mr Holmes was a psychiatric patient of Dr Fenton, and his communications with her are protected."
Holmes, who was studying neuroscience in a doctoral program at the University of Colorado Denver, is expected to be charged with 12 murders and 58 attempted murders at his next court appearance on Monday in connection with the July 20 shooting.
Fenton's research focuses on schizophrenia and other major mental illnesses.