An off-duty police officer having an early Valentine`s Day dinner with his wife was credited today with cornering Sulejmen Talovic, exchanging fire with him until other officers arrived to shoot and kill the gunman. The trench-coated teenager wanted to "to kill a large number of people" and probably would have killed many more if not for the off-duty officer, Police Chief Chris Burbank said. A friend said Talovic was from the war-torn country of Bosnia and that the trauma he experienced while growing up may have led to him snapping for some reason. Ken Hammond, an off-duty officer from Ogden, north of Salt Lake City, jumped up from his seat at a restaurant after hearing gunfire and cornered the gunman, exchanging fire with him until other officers arrived, Burbank said. "There is no question that his quick actions saved the lives of numerous other people," the police chief said. Police said it was not immediately clear who fired the shot that killed Talovic. Talovic had a backpack full of ammunition, a shotgun and a .38-caliber pistol, police said. Investigators knew little about Talovic, except than he lived in Salt Lake City with his mother, the chief said. He was enrolled in numerous city schools before withdrawing in 2004, the school district said. Initially, police refused to release his name or any information about his background. Talovic drove to the Trolley Square shopping center – a century-old former trolley barn with winding hallways, brick floors and wrought-iron balconies, and immediately killed two people, followed by a third victim as he came through a door, Burbank said. Five other people were then shot in a gift shop, he said. Four people who were wounded remained hospitalized today, two in critical condition, two in serious. Outside the mall, candles and flowers were left as memorials to the victims. Hammond`s boss, Ogden Police Chief Jon Greiner, said the state Senate wants to honor him. "Thank goodness he was there," said Greiner, who is also a state senator. "You don`t want to ever say it`s good we were there and killed somebody, but it`s probably good someone was there." Accountant Jeff Barlow was on a date at a restaurant when he looked outside and saw the gunman firing from the hip. "I thought it was some kind of joke – some kind of movie or stunt," Barlow said. "I didn`t believe it was happening. And then I saw a man go down in a courtyard. I realized this was serious. These are real bullets flying around." David Dean, who owns a greeting-card store at the mall, said three or four people died inside his store, which was packed with Valentine`s Day shoppers.