The psychiatrist's concerns surfaced in early June, nearly six weeks before the July 20 killings inside a movie theater in Aurora, sources told the Denver station.
Twelve people were killed and 58 wounded when James Holmes, 24, allegedly opened fire during a screening of the new Batman film. Holmes was charged Monday with murder and attempted murder in the case; he also faces two weapons charges.
A court document filed Friday revealed Holmes was a patient of University of Colorado psychiatrist Lynne Fenton before the attack.
Sources told KMGH that Fenton contacted several members of a "behavioral evaluation and threat assessment" team to say Holmes could potentially be a danger to others, the station reported.
The "BETA" team consists of "key" staff members from various university departments who have specific expertise in dealing with assessing potential threats on campus, the school says on its website.
Holmes was a doctoral student at the university's Anschutz Medical Campus until June, when he withdrew from the program.
Sources told KMGH that university officials never contacted Aurora police with Fenton's concerns before the July 20 killings.
"Fenton made initial phone calls about engaging the BETA team" in "the first 10 days" of June but it "never came together" because in the period Fenton was having conversations with team members, Holmes began the process of dropping out of school, a source told KMGH.
Sources told the station that when Holmes withdrew, the BETA team "had no control over him."
KMGH said sources did not know what Holmes told Fenton that sparked her concern.
"It takes more than just statements," one source told the station, explaining that Holmes would have had to tell Fenton "something specific" before she would have to report it to law enforcement.
"He would have to tell her he had taken steps to make it happen," another source told the station.
One source also told the station that the team may not have been convened because while Fenton had "serious concerns, there may not have been an immediate threat."
It's not clear if Fenton continued treating Homes after he dropped out of school, whether she referred him to another medical professional, or had any further contact with him, KMGH reported, citing sources familiar with the investigation.
Michael Carrigan, chairman of the CU board of regents, told KMGH he did not know if Holmes had ever been discussed by the BETA team, KMGH reported.
"It's the first I'm hearing about this," he reportedly told the station.
Authorities have remained silent about a possible motive in the case.
Prosecutors say they will begin turning over thousands of pages of discovery in the next couple of days. The defense says they need this information to prepare for the hearing.
During the week of November 12, attorneys expect a preliminary hearing and an evidence hearing that will include several days of testimony.