12/29/2025 - Report #840 - Victims: Elizabeth Hernandez-Sanchez and Yeisir Buster Concepcion - Location: Warren County, MO
MCS Report #840
Classification: Homicide
Requesting Agency: Warren County Sheriff’s Department
Date of Activation: 12/29/2025
Commander and Department: Det. Sgt. Russ McDermott, O’Fallon PD
Deputy Report Officer and Department: Det. Greg Buechner, Overland PD
Deputy Report Officer and Department: Det. Sgt. Wade McElfresh, O’Fallon PD
Victims: Elizabeth Hernandez-Sanchez and Yeisir Buster Concepcion
Suspect: Randys Miguel Ramírez Díaz
The Warren County Sheriff’s Department requested the assistance of the Major Case Squad in investigating the deaths of Elizabeth Hernandez-Sanchez (age 33) and Yeisir Buster Concepcion (age 42). At approximately 8:35pm, deputies responded to the area of South Stracks Church Road and State Hwy M for a report of a person down. When deputies arrived on scene, they located Yeisir Buster Concepcion lying on the ground outside of a vehicle with apparent multiple gunshot wounds. Deputies also located Elizabeth Hernandez-Sanchez inside the vehicle with an apparent gunshot wound. Both victims were declared dead at the scene.
Investigators learned Elizabeth and Yeisir were in a romantic relationship with each other. They had been traveling together in a vehicle when they were shot and killed.
Investigators developed information on a vehicle of interest and broadcast this information to surrounding police agencies. Warren County Deputies located a vehicle matching this description at a truck stop in Foristell around 3:00 a.m. on December 30. As Deputies attempted to contact the driver of the vehicle, identified as Randys Miguel Ramírez Díaz, he drew a gun and shot himself. He died at the scene.
It was determined Randys Miguel Ramírez Díaz had previously dated Elizabeth Hernandez-Sanchez. Based upon this investigation, detectives believe Randys Miguel Ramírez Díaz is responsible for shooting and killing Elizabeth Hernandez-Sanchez and Yeisir Buster Concepcion.
