A law enforcement official briefed on the investigation told The Associated Press that 24-year-old James Holmes has asked for a lawyer.
The official spoke on condition of anonymity to discuss the ongoing case.
The person also says police found jars of chemicals in Holmes' booby trapped Aurora apartment with wires nearby.
New York City's police commissioner says Holmes had painted his hair red and called himself the Joker - the villain from the Batman movies.
Aurora Police Chief Dan Oates would not confirm the information about suspected gunman James Holmes, but confirmed he had spoken to Kelly. The two used to work together in New York.