Dramatic emergency calls have been released by police investigating the Nebraska shopping mall massacre.Eight people were killed and five injured when teenage gunman Robert A. Hawkins opened fire on Christmas shoppers in Omaha before turning the gun on himself.The shooting spree prompted frantic messages to the emergency servicesThe 911 tapes released by the Omaha Police Department offer a look into the horror inside the busy Von Maur department store at the mall.The first call gave the chilling reality of what was going on inside the mall as an operator heard three gunshots but no one at the end of the phone line.Another call came from a woman inside the mall who said she was scared for her life. "I'm at Von Maur and I think there's shots being fired all over the place," she said.Hawkins, 19, went into the mall and fired more than 30 shots from a SKS 7.66 millimetre rifle in the Von Maur department store. Six store employees and two customers died in the hail of bullets.Hawkins was described by many as having a troubled past. He recently split with his girlfriend and had been fired from McDonald's.In May 2002, he was sent to a treatment centre in Missouri after threatening his stepmother.Four months later, a Nebraska court decided Hawkins' problems were serious enough that he should be under state supervision and made him a ward of the state.He went through a series of institutions in Nebraska as he progressed through the system: months at a treatment centre and group home in Omaha in 2003; time in a foster care program and treatment centre in 2004 and 2005; then a felony drug-possession charge later in 2005.The drug charge was eventually dropped, but he was jailed in 2006 for not performing community service as required.On August 21, 2006, he was released from state custody.Records in Sarpy and Washington counties showed Hawkins had a felony drug conviction and several misdemeanour cases filed against him, including an arrest 11 days before the shooting for having alcohol as a minor. He was due in court in two weeks.It was Nebraska's deadliest shooting since January 1958, when Charles Starkweather killed ten people in the state and another person in Wyoming.© Independent Television News Limited 2007. All rights reserved.