Las Vegas, NV - The shooting happened around 4:15 p.m. Saturday after security guard Mohamed Abdalla Mahmoud allegedly argued with his manager at a Ross Dress for Less store at the 4000 block Blue Diamond Road in the south Las Vegas Valley, police said.On Saturday, Capt. Nichole Splinter called the incident an isolated act of workplace violence after initial reports of an active shooter at the store.Jail records show Mahmoud, 37, was booked into the Clark County Detention Center and faces charges of attempted murder with a deadly weapon, two counts of assault and one of discharging a gun in an occupied building.Mahmoud did not hit the manager or anyone else in the store when he fired his weapon, police said. He then went outside and shot at arriving officers, they said.