After retiring from a 27-year career as a D.C. police officer, Harry Weeks thought working security at the US Holocaust Memorial Museum would provide a quieter way to make a living. A typical day involved greeting visitors and analyzing images of handbags as they passed through a magnetometer. The new job turned violent, though, when 50-year-old Weeks and another guard were forced to fire last Wednesday at a white supremacist who authorities said shot and killed one of their colleagues. The memory of that day is still raw, evident in Weeks' distant eyes and tense body as he described how he's used time with loved ones, cigarettes and prayer to help him cope. "It's not going to be the same anymore," Weeks said during an interview in the family room of his White Plains, Md., home. "You always knew that threat was there, well, I actually lived that threat." Weeks and the other guard who returned fire, Jason McCuiston, have been instructed by investigators not to discuss specifics of the shooting. Authorities have said the two fired at least eight times as accused gunman James von Brunn walked through the doorway after security guard Stephen T. Johns, 39, was gunned down. "It was just so surreal," said Weeks, who last fired his gun in the line of duty when he was 22. "Everything was just like in slow motion." Von Brunn, 88, has been charged with first-degree murder in Johns' death and remains hospitalized. He was hit in the face by gunfire, but the FBI has said he is likely to survive. Weeks was working at the magnetometer just before the shooting happened. McCuiston, a former Marine and police officer, stood next to him, handing items back to visitors once they were scanned. Foot traffic had slowed considerably around the lunch hour, Weeks recalls. The calm was shattered around 1 p.m., when authorities say von Brunn shot Johns in the chest with a vintage rifle after Johns, who was black, opened the door for him. "It was like uncommon valor," Weeks says of his fallen colleague. "He gave his life. He was where he was supposed to be. He was working his job - and he didn't come home that night." Johns, who'd been a security guard for six years, had been one of the first co-workers to greet Weeks after he started at the museum. Weeks became a security guard in late April, two months after retiring from the police department, where he'd worked as a patrolman and undercover officer before taking an assignment in forensic evidence. He said he'd decided to find a new job after tiring of days spent playing golf. The job with with Wackenhut Services Inc. was an attractive opportunity because he'd get to see different people and, he says, he didn't think it would be like law enforcement. The day of the shooting was supposed to be a day off, but Weeks and 30-year-old McCuiston were asked to work overtime to help with the expected large crowds for the debut that evening of a play about racial tolerance. "We'll never be the same again," Weeks said. Wackenhut has told Weeks and McCuiston that they can return to work whenever they're ready. Both intend to go back, Weeks says. If they didn't, it would signal that types like von Brunn would "win out." "I have to go back," Weeks said. "To see those people again; I need to see the people I work with."