Detective Sergeant Lemkemeier was shot and killed when he and Detective Charles Shelton stopped to question three suspicious men, Louis Trider, an escaped convict; Nick "Shoes" Serb, an escaped convict; and Serb's wife outside of a pool hall after Detective Shelton recognized Serb. The three were in the process of planning the robbery of an payroll courier in Wood River, Illinois. When Detective Sergeant Lemkemeier contacted the three and when asked what they were doing Serb advised him that they were waiting for a friend and that Trider was going to drive them to Alton, Illinois. Detective Shelton went into the pool room to check it out. Detective Lemkemeier walked around to the driver's side of the vehicle and asked the driver, Trider, who he was. Trider shoved Sergeant Lemkemeier away, pulled a revolver and shot Sergeant Lemkemeier. Trider leaned out of the car and shot Sergeant Lemkemeier again as he sank to his knees, took a hot at Detective Shelton as he exited the pool room, then drove away. Detective Shelton fired on the suspect's vehicle, commandeered a truck and had the driver follow the suspect vehicle continuing to fire at them until he emptied his revolver. The suspects pulled away and escaped.

Detective Shelton returned to the scene to find that Sergeant Lemkemeier had sustained a fatal gunshot wound to his back with the bullet lodging near his heart.

The convict, Trider, was able to elude officers until October 1922 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. Trider also murdered a Ray County Deputy Sheriff the day after he killed Sergeant Lemkemeier.

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. Interred: Mt. Zion Cemetery.  

Related memorial page: Deputy J. Edward Lee - Ray County Sheriff's Department