An off-duty security guard has been charged with murder after authorities say he stopped three teens outside a store near Seattle because they had what he believed was a firearm, but it was actually an airsoft pistol. King County prosecutors charged Aaron Brown Myers on Monday with second-degree murder in the death of 17-year-old Hazrat Ali Rohani outside a Big 5 Sporting Goods Store in Renton, Washington, the AP reports. Myers, 51, also faces a second-degree assault charge after authorities say he held another teen at gunpoint. What happened: