AURORA, Colo. — Federal and local authorities on Saturday began disarming the booby-trapped apartment of a man suspected in the deadly mass shooting at a movie theater here, neutralizing many of the sophisticated explosive contraptions in his apartment while trying to preserve evidence that might offer insight into the rampage.


Sgt. Cassidee Carlson of the Aurora Police Department said Saturday afternoon that bomb specialists had eliminated the major threats in the apartment, making it safe to enter.


But “there still remains all kinds of hazards inside the apartment,” Sergeant Carlson said at an afternoon briefing. “We will remain here for hours to collect evidence and mitigate those hazards.”


Police had disabled a second triggering device, she said, but the only way of knowing if all threats had been eliminated would be by entering the apartment.


Initial spasms of shock and anger turned to raw, open sadness here on Saturday as police completed the grim task of informing families whose relatives were among at least a dozen people who died in the shooting early Friday during a midnight screening of “The Dark Knight Rises.”


Many people took to Facebook and Twitter to express their grief, a sign of the increasing importance of social media during mass tragedies.


More than 50 people were injured, some critically, during the shooting that upended an evening of excitement that brought families and many young people out for the highly anticipated Batman sequel.


The authorities had worked through the night to identify those killed, and by Saturday morning they said they had notified all the families of victims, including some who had been holding out hope that those missing had been spared. There were still 11 people hospitalized in critical condition, the authorities said.


The authorities did not immediately make public a list of the dead, but many family members came forward on their own to identify the victims.


Among those identified so far were a 6-year-old, two active-duty servicemen, a 23-year-old community college student, a young man celebrating his 27th birthday, and a sports blogger who a month ago had narrowly avoided a shooting spree at a Toronto shopping mall.


Candlelight vigils were held across the city on Friday night. A shrine to the victims was set up outside the movie theater, and one of the local high schools planned another memorial Saturday evening.


“Cant believe your gone man,” Christopher Marmaro wrote on the Facebook page of Alexander Boik, who went by A.J., a 17-year-old who friends said attended the movie with his girlfriend. “It breaks my heart.”


The tragedy prompted a rare bit of bipartisan accord in Washington.


President Obama used his weekly radio address to again speak out on the shootings, saying, “Such evil is senseless — beyond reason.”


“If there’s anything to take away from this tragedy, it’s a reminder that life is fragile,” Mr. Obama said. “Our time here is limited, and it is precious. And what matters in the end are not the small and trivial things which often consume our lives. It’s how we choose to treat one another, and love one another. It’s what we do on a daily basis to give our lives meaning and to give our lives purpose. That’s what matters. That’s why we’re here.”


House Speaker John A. Boehner gave the Republican response to the president’s radio address, saying that he had planned to speak on the economy, but instead directed his attention to the shootings.


“Words cannot capture the horror, or make sense of something so senseless. So I won’t try,” he said.


Led by the Bureau of Alcohol, Tobacco, Firearms and Explosives, law enforcement agents began early Saturday securing the area around the apartment of the suspect, James Holmes, 24, where they found a complex maze of wires and chemicals that they feared could be explosive. The apartment is a few miles from the multiplex where the shootings occurred.


Residents in five buildings surrounding Mr. Holmes’s were evacuated on Friday. Sixteen of the evacuated were taken to shelter at Central High School, where 12 people joined them late Friday night after an unrelated fire at an Aurora apartment building forced them from their homes.