Batman cinema shootings: police prepare to enter suspect's flat Holmes had purchased 6,000 rounds of ammunition over the internet before the massacre, police said. He was carrying a Glock pistol, a 12-guage shotgun and a high-powered AR-15 assault rifle fitted with a drum magazine. Another Glock pistol was found inside his car that had been parked outside a fire exit. Dozens of law enforcement officials arrived at the apartment of suspect James Holmes at dawn on Saturday, but were unable to enter the top floor flat after investigations using a pole mounted camera revealed the booby traps. Aurora police chief Dan Oates said photographs from inside the building revealed it the apartment contained "things that look like mortar rounds." He added: "I've personally never seen anything like what we've found in there." Firefighters have also been conducting tests on any gases being given off from inside the flat in an attempt to identify what chemicals might have been used in the booby traps. Meanwhile hundreds of mourners gathered for a vigil near the cinema in Aurora on Friday night, leaving candles and flowers outside in memory of those who had been killed. Thirty people remain in hospital with 11 of those in a critical condition. Police declined to say what, if anything, Holmes said to them following his arrest. The motives for the massacre are still unclear and police have refused to say if they have managed to establish any possible reason for the attack. Holmes had no criminal record other than a speeding fine while friends and family described him as a "nice guy" who had shown no signs that he might be dangerous. Holmes' family issued a statement of sympathy for the victims, saying: "Our heart goes out" to their loved ones, while they also asked for privacy from the media while they "process this information." President Barack Obama called the shootings a reminder that life is fragile and promised that the federal government stood ready to do all it could to seek justice for the "heinous crime."