On a cold January morning in Joliet, Illinois, the life of 4-year-old Gianni Reyes was tragically cut short. On January 25, 2026, Gianni and his 36-year-old mother, Joselynn Diaz-Garcia, were found with fatal gunshot wounds in the backyard of their home on Garnsey Avenue. The devastating discovery was made after neighbors reported hearing multiple gunshots just before 7 a.m.
Responding Joliet police officers arrived to a grim scene.
Inside the home, a 9-year-old boy with special needs, believed to be Gianni's older brother, was found physically unharmed. The tranquility of the neighborhood was shattered as investigators began to piece together the events that led to the double homicide. Witnesses reported seeing a shirtless man running from the scene and discarding a firearm near some railroad tracks.
A person of interest, 29-year-old Joseph D. Johnson of University Park, was soon located. Johnson, who court documents indicated also lived at the Garnsey Avenue residence, was taken into custody after being found with a self-inflicted gunshot wound to his ankle. Police recovered a firearm nearby, and the shell casings at the scene appeared to match the weapon. Investigators have suggested a possible domestic relationship between Johnson and Diaz-Garcia.
Following the incident, Johnson was hospitalized at Loyola Medical Center under police guard. While still recovering from his injuries, he was charged with six counts of first-degree murder in connection with the deaths of Gianni Reyes and Joselynn Diaz-Garcia. Upon his release from medical care, Johnson will be transferred to the Will County Adult Detention Facility to await legal proceedings. The investigation into the double homicide remains active.
