Two adults and one child were fatally shot in an incident police are calling a possible home invasion outside Chicago on Sunday night. A suspect was found and detained in connection with the killings, authorities confirmed on Monday morning.

Officers in Bolingbrook, a suburb southwest of Chicago, responded to a call reporting a potential home invasion in the area at around 8:15 p.m. on Sunday, the Bolingbrook Police Department said in a news release.

When police arrived at the address, they discovered three adults and one child who had each been shot, according to the news release. A man, woman and a girl were all pronounced dead. The fourth person shot, who police identified as a woman, was transferred to a local hospital for treatment. 

On Monday morning, police confirmed a suspect had been detained. “Our patrol officers and investigators are working diligently on all potential leads and evidence at this time,” they said.

Authorities are asking anyone with information about the shooting to report what they know to the Bolingbrook Police Department, or to Crime Stoppers if they wish to share tips anonymously. Police said on Sunday night that a cash reward may be given for information leading to an arrest, but it was unclear on Monday how the investigation ultimately led officers to the suspect in custody, and whether community tips were involved.

After the shooting, a neighbor told CBS Chicago that he does not know the family whose Bolingbrook residence may have been targeted in the potential break-in on Sunday, but he has seen law enforcement at the home multiple times before. Another neighbor called the attack “very devastating” in comments to the station.