Detective Sergeant Lemkemeier was shot and killed when he and another detective stopped to question three suspicious men outside of a pool hall. One of the men was an escaped convict and the three were in the process of planning an armed robbery of a payroll courier. When Detective Sergeant Lemkemeier asked the driver who he was the suspect produced a revolver and opened fire, fatally wounding Detective Sergeant Lemkemeier. All three fled the scene and two were quickly arrested. The convict was able to elude officers until October when detectives received word he was returning to St. Louis. The detectives setup a sting and attempted to arrest him as he stepped off of a streetcar. When he produced his revolver the detectives opened fire, killing him. Detective Sergeant Lemkemeier was in charge of the Homicide Squad. He had been with the agency for 15 years and was survived by his father and two brothers, one of whom was also a detective.