ROYAL OAK CHARTER TOWNSHIP, Mich. – Police are investigating a Dollar Tree store armed robbery that took place on Friday at around 9 p.m. in Royal Oak Charter Township. According to witnesses, a black man wearing a hoodie and face mask was in the store making cash purchases before the robbery. The robber returned after all the customers left. He pulled out a gun and threatened to shoot two employees for money from the register. Police say the robber left the store on foot and no one was injured.