On the morning of April 26, 2017, a violent incident unfolded in the Pine Lawn neighborhood of St. Louis County, Missouri, resulting in the loss of three lives. Authorities were dispatched to the 4500 block of Rosewood Avenue around 10:13 a.m. following reports of a shooting. Upon arrival, first responders discovered a chaotic scene where three men had been fatally wounded.
Among the victims was 23-year-old Marquise Jamar Cooper, an African American male who was pronounced dead at the location alongside two other men, identified as 29-year-old Calvin Walker and 29-year-old Andrew Green.
The victims were found in separate areas of the immediate vicinity, indicating a scattered and frantic sequence of events. One of the men was discovered inside a black SUV, while another was found lying on a nearby sidewalk. The third victim was located in the yard of a residence. All three had sustained apparent gunshot wounds that proved fatal before emergency medical personnel could intervene. The nature of the triple homicide prompted the North County Police Cooperative to request the assistance of the Major Case Squad of Greater St. Louis to lead the investigation.
Detectives immediately began canvassing the area for leads, focusing their search on two vehicles believed to be connected to the crime. Law enforcement released descriptions of a white, older-model Chevrolet Impala equipped with a black spotlight, resembling a police vehicle, as well as a black Nissan Altima. Investigators appealed to the public for any information regarding these cars or the individuals who might have been operating them at the time of the murders.
Despite the involvement of the Major Case Squad and the collection of evidence from the scene, the case faced significant challenges. In the years following the tragedy, family members of the victims expressed their anguish over the lack of progress, fearing the investigation had gone cold. Reports indicated that no immediate arrests were made in connection with the deaths of Cooper, Walker, and Green, and the case remained classified as an open homicide with the suspects strictly listed as unknown. Rewards were offered through regional crime stoppers for information leading to a felony arrest, as the families continued to wait for answers and justice.
