Janesville police are investigating the armed robbery at a retail store on the west side. Lieutenant Todd Kleisner says two young men with handguns walked into the Dollar General on West Court Street just before 10:00 p.m. Wednesday night. Kleisner says they demanded cash an fled on foot. A K9 unit was brought in to track the two, but was unsuccessful. A patrol officer making a traffic stop about 45 minutes later was able to make one arrest. Interviews with the car’s occupants led to a second suspect who was arrested at a south side home sometime after midnight.