On January 25, 2026, 4-year-old Gianni Reyes and his 36-year-old mother, Joselynn Diaz-Garcia, were found fatally shot in the backyard of their Joliet home on Garnsey Avenue after neighbors reported multiple gunshots shortly before 7 a.m. A 9-year-old boy with special needs, believed to be Gianni’s older brother, was inside the house and was physically unharmed when officers arrived.

Witnesses said a shirtless man ran from the scene and discarded a firearm near nearby railroad tracks. Police located 29-year-old Joseph D. Johnson of University Park, who court documents indicate also lived at the Garnsey Avenue residence; he was found with a self-inflicted gunshot wound to his ankle and taken into custody. A firearm was recovered nearby, and shell casings at the scene appeared to match that weapon. Investigators have suggested a possible domestic relationship between Johnson and Diaz-Garcia.

Johnson was hospitalized under police guard and has been charged with six counts of first-degree murder; upon release from medical care he is to be transferred to the county jail. The investigation into the double homicide remains active.

If anyone knew Gianni, Joselynn, or the household and has information that could help investigators, please come forward.