Officials at the Illinois university offered to admit James Holmes and give him a stipend, 176 pages of documents released by the school Friday indicated.
In the documents, Holmes described himself as an "aspiring scientist" when he applied for admission to UI's neuroscience department in early 2011, CNN reported.
A letter of reference from one of his former professors described Holmes as bringing "a great amount of intellectual and emotional maturity into the classroom."
Holmes visited the Champaign campus in March 2011 and met with the department head, professors and research assistants.
The university decided to admit him and offered a $22,600 stipend and waivers of tuition and fees.
Holmes turned down the offer without explanation. About the same time he was accepted to the University of Colorado in Aurora.
Holmes dropped out of UC's graduate program about a month before the July 20 shooting spree at a midnight showing of the Batman movie "The Dark Knight Rises," in which 12 moviegoers were killed and 58 were wounded.
The University of Colorado has declined to release Holmes' records, citing a judge's order sealing all documents related to Holmes' murder trial.