CENTENNIAL, Colo. – Police officers who arrested James Holmes after the Colorado movie theater massacre described the suspected gunman, clad in body armor, as unusually relaxed but fidgety at times.

Holmes didn’t resist arrest behind the theater and volunteered that his apartment had been booby trapped, the officers testified during the opening of a hearing in which prosecutors began laying out their case against the former neuroscience graduate student.

Officer Jason Oviatt said Holmes seemed “very, very relaxed” and didn’t seem to have “normal emotional reactions” to things.