Police defuse booby-trapped flat of Batman massacre suspect

Police explosives experts on Saturday neutralized booby traps and bombs in the apartment of James Holmes, a day after the suspect allegedly killed 12 and injured 59 at a midnight screening of the new Batman movie in the city of Aurora, Colorado, DPA reported.

Law enforcement officials said that the complex series of devices in the third-floor flat were designed to kill whomever entered, providing another clue about the calculated mindset of the 24-year-old neuroscience graduate student who is to be charged Monday in the movie theatre rampage.

"We believe we have eliminated the major threats there, but we still have some more work to do," said Aurora police chief Dan Oates at a news conference Saturday afternoon. There was no question, Oates said, that the apartment was "designed to kill whoever entered it," and most likely it would have been a police officer.

Jim Yacone, FBI special agent in charge for Denver, said at the same news conference that the threat at the apartment was not over, but was greatly reduced.

According to USA Today the living room of the small apartment was filled with fireworks shells that had been converted to function like grenades, which authorities were going to remove and detonate at a remote location.

The news conference came after explosives experts used a bomb disposal robot to neutralize trip wires and other bomb components and later ignited a small explosive in the apartment as teams of firemen were stationed around the surrounding areas in case of a mishap. Oates said that dozens of residents who had been evacuated could be allowed home later Saturday.

"This trip wire was set up to clearly detonate when somebody entered the apartment, and it was set up to kill that person," Sgt Cassidee Carlson told CNN.

Oates said Holmes appeared to have amassed the ammunition he used in the attack and apartment booby traps via large mail order deliveries in recent months. "What we are seeing here is evidence of some calculation and deliberation," Oates said.

Police were also still collecting evidence in the movie theatre where the attack took place. Eleven of those injured in the assault remain in critical condition, officials said at the news conference.

Holmes allegedly launched his devastating attack shortly after midnight on Friday as Batman fans packed into a local cineplex to view the eagerly awaited Dark Knight Rises, which was expected to have one of the best opening weekends of all time.

Wearing a helmet, a gas mask and protective body gear, Holmes is said to have detonated two gas canisters in the crowded theatre before spraying the audience with gunfire from an assault rifle, shotgun and two handguns he had bought legally in recent weeks. Many eyewitnesses said that they thought the gunshots were part of the movie or fireworks.

Holmes surrendered without resistance to police in the parking lot behind the theatre, within 90 seconds of the first emergency call being received, Oates said.

The harrowing incident has rekindled debate in the US over tighter regulation of guns, an idea strongly opposed by the Republican Party and the powerful National Rifle Association, one of the country's most formidable lobbying organizations.