AURORA, Colo. (AP) — The Colorado shooting suspect planned the rampage that killed 12 midnight moviegoers with “calculation and deliberation,” police said Saturday, receiving deliveries for months which authorities believe armed him for battle and were used to rig his apartment with dozens of bombs.

Authorities on Saturday were still working to clear dangerous explosive materials from inside James Holmes’ suburban Denver apartment a day after police said he opened fire and set off gas canisters in a suburban theater minutes into the premiere of the Batman film “The Dark Knight Rises.” The attack left 12 dead and 58 injured.