HARVEY, Ill. (WLS) — The Harvey Police Department will provide an update Monday on Saturday night’s mass shooting and an apparent retaliatory killing that happened Sunday.

A Concealed-Carry License holder fatally shot one of two gunmen who injured a young child and four others at a house party on Saturday night, officials said.

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Officials believe another deadly shooting, which happened on Sunday morning, may be connected to Saturday night’s mass shooting.

On Sunday, crime tape and evidence markers are the only signs left of Saturday night’s shooting, which happened around 8 p.m. during a house party on the corner of 145th and Des Plaines. Neighbors described the scene to ABC7.

“It was chaotic. A lot of police. A lot of ambulances. A lot of people laying on the ground. It was a shame to have to see something like that,” said neighbor Terrence Simpkins. “It was a sad moment for this community here. And more work needs to be done.”

Two armed men opened fire at the gathering, injuring five of the guests. But it did not end there. A CCL holder who was present returned fire, killing one of the suspects and injuring the other.

A 4-year-old boy suffered non-life-threatening injuries and is listed in stable condition.

Four other party attendees also suffered gunshot wounds. They were taken to local hospitals in stable condition.

The suspect killed was pronounced dead on the scene.

The injured suspect was taken to a hospital in stable condition, and is now in police custody.

While police initially believed Saturday’s shooting to be an isolated incident, saying there was no further threat to the community, they are now investigating an early Sunday morning shooting, which happened in the 200-block of Calumet Boulevard, as a possible act of retaliation.

A man was found dead inside a minivan. The medical examiner later identified him as 28-year-old Jeremiah R. Adtutubofah.

One neighbor, who did not want to show her face, spoke with ABC7.

“I woke up, and it sounded like bullets were hitting the garbage cans… I heard, at least 40, 38, I don’t know, a lot of rounds,” she said. “I ran downstairs and grabbed, just everyone away from windows, just threw them to the floor.”

While the search for the gunman in Sunday morning’s fatal shooting continues, a spokesperson for the Harvey Police Department said investigators are actively following leads and witnesses are cooperating.

Further information was not immediately available.

Cook County 5th District Commissioner Dr. Kisha E. McCaskill issued a statement, saying, “I am heartbroken and outraged by the senseless acts of violence that took place in our community this weekend. What should have been a peaceful gathering at a home on Des Plaines Street turned into a tragedy that left one person dead, six others wounded – including a 4-year-old child-and a neighborhood shaken to its core. Just hours later, another life was lost on Calumet Boulevard, in what appears to be a retaliatory act.

My thoughts are with the families of the victims, especially those now tending to the trauma and physical wounds of their loved ones. No child should ever have to experience the terror of gunfire. No parent or resident should ever fear that a community celebration will end in chaos. These victims are our neighbors, our friends, our children.

To the residents of Harvey: we must come together. Violence cannot and will not define who we are. I am in close contact with our police department and investigators, and I want to commend those who have already stepped forward to assist in this ongoing investigation. Your courage brings us one step closer to justice.

But we need more than just justice after the fact. We need prevention, intervention and long-term investment in the safety and well-being of our neighborhoods. That includes working with community leaders, faith organizations, educators and families to interrupt cycles of violence before they take hold.

I am calling on every resident, every stakeholder, and every partner-from law enforcement to state officials-to stand with us in healing and rebuilding. We will be organizing a community town hall and vigil in the coming days to honor the victims and to begin a deeper conversation about real solutions.

We cannot undo what happened this weekend, but together, we can choose a different path forward.”

The video in the player above is from a previous report.