For the thrid time in six months, the Ames Police Department is investigating the armed robbery of a west side convenience store. Police say the Swift Stop at 3406 Lincoln Way was held up at about 3:45 Wednesday monring. Police say the suspect showed a gun a took an undisclosed amount of cash. The suspect is described as a light-skinned black or hispanic male, 5'8" to 5'10" wieghing between 160 and 200 pounds. The suspect was wearing dark clothing at the time of the crime. The Swift Stop is he same store that was robbed back in November and again in March.