US President Barack Obama is to visit Colorado to honour victims of Friday’s gun attack at a Batman film screening that left 12 people dead.The White House said Mr Obama would meet survivors and families of victims, as well as local officials in Aurora.In his weekly radio address, he called for prayer and reflection on the gun rampage in the Denver suburb.Pope Benedict has voiced "deep shock” over the attack which left another 58 people injured, some critically.James Holmes, 24, currently being held in solitary confinement for his own safety, is alleged to have opened fire during a packed midnight screening of The Dark Knight Rises.People have been laying flowers near the Century cinema, where the shooting occurred.An evening vigil, organised by local community and religious leaders, is due to take place in front of Aurora city hall later on Sunday.Mr Obama’s visit comes a day after police cleared James Holmes’s flat of explosives which could have killed people entering via the door.Both Mr Obama and his Republican Party challenger, Mitt Romney, curtailed their election campaigns in the wake of the Aurora attack, dropping advertising in Colorado state out of respect for victims and their families.The FBI is now collecting evidence from the flat of Mr Holmes, who is accused of at least 12 counts of first-degree murder.Booby traps connected to explosives had prevented police from entering it for two days until they made the devices safe.Police said the suspect had acted with "calculation and deliberation”, taking ammunition deliveries for months.Aurora police chief Dan Oates said: "I’ve personally never seen anything like what we’ve found in there.”"This apartment was designed to kill whoever entered it,” he said, adding that would most probably have been a police officer."If you think we are angry, we sure as hell are angry about what has happened to our city, to the wonderful people who live here and what he threatened to do to one of our police officers.”James Holmes is due to appear in court on Monday.Authorities have established no terrorism link, nor any motive. Mr Holmes had no criminal record other than a speeding fine.The Arapahoe county coroner Michael Dobersen has now released the names of the dead.He said all the deaths were related to gunshot wounds.The dead include a six-year-old girl and two US military servicemen.The University of Colorado Hospital said it was still treating five patients in critical condition and the Medical Center of Aurora said four of its patients remained in intensive care.Local mayor Steve Hogan told a memorial service for a young victim on Saturday that the community in Aurora was still reeling from the "unbelievable tragedy”.Agencies