Police gained access Saturday to Holmes' apartment after intentionally detonating two rigged explosives.
Technicians, with the help of a robot, worked to handle traps, wires and possible explosive and incendiary devices, Jim Yacone, a special agent with the FBI, told reporters Saturday.
The operation proceeded with an eye toward preserving evidence, all of which will be sent to an FBI lab in Quantico, Virginia, Yacone said. Among the items seized from the apartment were a Batman poster, Batman mask and a computer, according to the law enforcement source. The shootings occurred during a screening of the new Batman movie, "The Dark Knight Rises."
Hundreds of residents were evacuated from five buildings, including the modest, three-story brick building where Holmes told the police he had rigged his top-floor, one-bedroom apartment with explosives. All occupants except those who live in the suspect's building were allowed to return home Saturday night.