Holmes has been charged with 24 counts of first degree murder - two counts for each of the 12 people shot dead during a midnight screening of Christopher Nolan's The Dark Knight Rises on July 20.
According to The Hollywood Reporter, Holmes was barred from the University of Colorado after threatening a professor in his graduate programme.
Prosecutor Karen Pearson released documents on Friday (August 24) suggesting that Holmes informed a university classmate he planned to kill prior to flunking and subsequently withdrawing from school.
Lawyers for Holmes claim that he is "mentally ill".
His psychiatrist Dr Lynne Felton apparently noted Holmes's increasingly erratic behaviour prior to the shooting.