Investigators have taken the "prime suspect" in the Halloween party shooting that killed two people and injured nine others in Joliet Township into custody, the Will County Sheriff's Office said.
An 18-year-old was placed into custody after sheriff's detectives analyzed interviews, videos and tips related to the shooting, according to a social media post.
The sheriff's office noted that the teen had an active Will County warrant on unrelated weapons offenses that occurred while he was a juvenile. On Wednesday, officials obtained a search warrant for the teen's Joliet residence.
After arriving at the residence, deputies knocked on the door and announced their presence when they saw the teen look out of a second story window, then disappear, according to the social media post.
Officials said deputies saw a gun had been placed outside the same window onto the roof of the first floor. After entering the residence, deputies placed the teen into custody and took a semi-automatic 9mm Glock into evidence.
The teen was charged with aggravated unlawful use of a weapon, obstructing justice and illegal possession of ammunition, authorities said. The teen is being held on a $1 million bond.
No charges are related to the deaths nor the shooting in Joliet Township at this time, officials added.
The shooting occurred at approximately 12:39 a.m. Sunday when two men opened fire into a crowd of approximately 200 people that had gathered at a backyard party in the area of Jackson and Walnut streets.
Residents initially invited friends using social media, police explained, but the invitation spread and attracted numerous people who weren't associated with the hosts.
The crowd scattered moments after shots erupted, ultimately resulting in some people being injured in the chaos.
Holly Matthews and Jonathan Ceballos, both 22, both died from their injuries, according to the Will County Coroner's Office.
A total of nine people were transported to the hospital with injuries including gunshot wounds and others sustained fleeing the scene.
As of Monday, three people remained in the hospital with non-life threatening injuries while a fourth person was said to be in critical condition, according to law enforcement.
Five people had been treated and released.
Prior to the shooting, a Will County sheriff's deputy responded to noise complaints in the area, but didn't receive any calls originating from where the party took place.
The deputy remained in the area, and when shots were fired, responded to the scene immediately, according to police.
While the investigation remains underway, it's believed the shooting was gang-related. Detectives have collected a "substantial amount" of evidence, police stated, and continue to interview witnesses, but say some have been uncooperative.
"...With the amount of attendees at this party, we are most certain that several people know who committed this atrocious and deadly shooting," sheriff's authorities added." The Sheriff’s Office is imploring those people to come forward in order to bring justice to the survivors, deceased victims, and their families."
Anyone with information about the suspects is asked to contact the Will County Sheriff’s Office at 815-727-8575. Individuals who wish to remain anonymous can also reach out to Will County Crime Stoppers at 800-323-6734.