Detective Sergeant Lemkemeier was shot and killed when he and Detective Charles Shelton stopped to question three suspicious men.

On July 26, 1922 at a little after 1 pm, Detective Sergeant Lemkemeier and Detective Charles Shelton were driving by a pool room at 914 Biddle when Detective Shelton recognized Nick Serb among others sitting in a vehcle. Serb was in the midst of a meeting with Louis Trider. Trider was discussing his plan of robbing a payroll courier in Wood River, Illinois and he need Serb for a driver. Sergeant Lemkemeier stopped their car and the detectives and approached Serb and Trider. Sergeant Lemkemeier said there was probably a moonshine party going on in the rear of the pool room. 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, Louis 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, then took a shot at Detective Shelton as he exited the pool room and 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 lodged near his heart.

The convict, Trider, was able to elude officers until October 12, 1922 when detectives received word he was returning to St. Louis. The detectives setup a sting in cooperation with East St Louis detectives and attempted to arrest him as he stepped off of a street car in East St Louis. When he produced his revolver the detectives opened fire, wounding him twice. Trider was taken to a hospital under heavy guard where he died on the same date from his injuries. Trider also murdered Ray County Deputy Sheriff Edward Lee the day after he killed Sergeant Lemkemeier. Trider was also wanted for escape from a penitentiary in Kentucky where he had been serving time for killing a police officer in Louisville.

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