CAPITOL HEIGHTS, Md.—Two staff members were fatally shot Friday at a Maryland apartment complex for seniors just outside of Washington and a suspect was taken into custody, police said. The shooting happened shortly after 9 a.m. at Gateway Village in Capitol Heights, Prince George’s County and Capitol Heights police said. Both victims were women—one found in a hallway and another in an office, they said. A resident who identified himself only as Donald said the shooter is his friend and lived in the complex. He said the man was fed up with how residents have been treated. “He told me, ‘Don, nobody is standing up for these seniors. I can’t take it no more. I’ve got to do something.’ And obviously what he chose to do is wrong, but he did something,” the resident told reporters. Gateway Village is one of 310 communities in 25 states run by National Church …