(RNN) – James Eagan Holmes, the suspect in the deadly shooting at an Aurora, CO, theater, mailed a notebook to a professor that may have detailed plans of a mass killing, multiple sources have reported.
An unnamed law enforcement official was quoted by FoxNews.com as saying Holmes mailed a notebook to the professor, who also treats patients at the University of Colorado Anschutz Medical Campus. The notebook apparently got held up in the school's mail-delivery system, according to the report.
The Denver Post also talked to the unnamed source, who confirmed Holmes mailed the notebook to the psychiatrist. However, the source could not tell the Post what the notebook contained.
NBC News cited a law enforcement official that said Holmes told investigators to look for the package on campus. The notebook Holmes allegedly mailed contained writings about killing people, according to the source.
The University of Colorado Anschutz Medical Campus released a statement on its mail delivery procedures, but declined to comment further on the notebook.
"The University centrally receives mail from the United States Postal Service. The University then delivers the mail to the address on the Anschutz Medical Campus the same day it is received," the statement said. "The University's mail service is not open on Saturday. Saturday mail is sorted and delivered Monday morning. The University does not log or track mail/packages unless it requires a signature from the United States Postal Service."
FoxNews.com gave conflicting reports on when the notebook arrived in the school's mailroom, possibly as early as July 12. The package was not opened until Monday night after it was confiscated while authorities executed a search warrant, according to the site.
It was unclear why the psychiatrist was the intended recipient of the notebook.
The Aurora Police Department has not given updates or issued other statements since Arapahoe County District Judge William Sylvester issued a gag order Monday.
FBI Denver Agent Dave Joly and the university also declined to comment on the matter.
The university reported receiving two suspicious packages Monday - one to a faculty member and another to campus mail services, according to the Post.
The professor received a package with Holmes' return address, according to FoxNews.com.
It could not be verified that Holmes and the professor had previous contact.
Holmes had dropped out of the university's neuroscience doctoral program before the alleged shooting.
He is accused of killing 12 people and injuring 58 others in the mass shooting during the midnight screening of The Dark Knight Rises.
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