A tragic incident unfolded over the weekend in Joliet, Illinois, as a 29-year-old local man faces murder charges in the deaths of a mother and her young child. Authorities announced these developments on Wednesday.

Joseph D. Johnson has been formally accused of first-degree murder following the fatal shootings of Joselynn Diaz-Garcia and her 4-year-old son, which occurred on Sunday, according to police reports.

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Currently, Johnson is under police supervision at Loyola Medical Center in Maywood as he receives medical treatment, as per statements from the Joliet police.

Upon his release from the hospital, he will be transferred to Will County Jail to await further legal proceedings.

The Joliet police department received emergency calls at approximately 6:55 a.m. on Sunday morning, alerting them to gunfire near the intersection of Cleveland and Dillman avenues. Witnesses reported seeing a shirtless man firing a gun while running alongside train tracks.

Officers swiftly responded to the situation, arriving at a residence located in the 700 block of Garnsey Avenue on the city’s east side to investigate the incident.

There, officers found a 29-year-old man who had suffered an apparent self-inflicted gunshot wound to his ankle, police said.

Outside the home, officers found the 4-year-old boy and his mother, a 36-year-old woman, unresponsive near the backyard. Both victims suffered apparent gunshot wounds and were pronounced dead on the scene.

Officers also found an unharmed 8-year-old boy, who has special needs, in a bedroom. The boy, who is also the 36-year-old woman’s child, was taken to a local hospital as a precaution.

A motive for the shooting was not immediately clear, but police said it appears that the person of interest and the victims had some kind of domestic relationship.

Police said the 29-year-old is believed to be a part-time resident of the home, and he is not believed to be the father of the two boys.

“On behalf of the Joliet Police Department, I extend our deepest condolences to the family and to everyone in our community who is touched by this awful and unnecessary act of violence. I am incredibly proud of our officers, detectives, and dispatchers who acted swiftly and professionally under heartbreaking circumstances. We will continue to seek justice while surrounding this family and our city with compassion and support,” Joliet Police Chief Bill Evans said.

Joliet police continue to investigate the double fatal shooting.

Anyone with video footage or information related to the incident is encouraged to call the Joliet Police Department Investigation Division at 815-724-3020, or contact Will County Crime Stoppers at 800-323-6734 or online at to remain anonymous.