Three armed robberies on Rockford's northwest side are under investigation. Police say a woman was robbed at gunpoint near the intersection of Latham and Midway shortly before 7 p.m. Monday. The woman tells police a man with a gun stole her purse before he got away in a silver Chevy Impala. The suspect is described as a black male in his mid 20's. He's 5'6 and 150 pounds. Police say the suspect was wearing a white hooded sweatshirt and a black stocking cap.  Police say a man was robbed near the intersection of Pierce Avenue and Ruth Street shortly after 7 p.m. Monday. The victim tells police he was approached by three suspects who pointed guns at him and went through his pockets. The suspects apparently didn't get anything. Police say the suspects fled westbound on Barton Blvd in a silver Chevy Impala.  Police say a man walking near Riverside Blvd and Eagle Drive was robbed last night by a suspect with an assault rifle. Police say the suspect stole the victim's cash and credit cards. The suspect fled in a gray or silver Chevy Impala. Police are investigating whether the same people are responsible for all three robberies. So far...no arrests.