CATOOSA, Okla. − A suspect and a person of interest wanted in connection to the weekend mass slaying of a couple and their two young children in Illinois are dead following a fatal police chase nearly 700 miles away in Oklahoma, police said.

Nathaniel Huey Jr., 31, of Steamwood, Illinois, and a woman not yet identified by law enforcement, were found fatally shot inside a vehicle in Catoosa, Oklahoma, just northeast of Tulsa.

Just three days earlier, Romeoville Police Deputy Chief Chris Burne said, officers found a couple, their two young children and the family's three dogs fatally shot at their home in Romeoville, a small village about 30 miles southwest of Chicago.

Earlier this week, police said the family's killing was not a random act of violence, but targeted.

The Will County Coroner’s Office identified the family as Alberto Rolon, 38, and Zoraida Bartolomei and their two boys, age 7 and 9. Authorities have not released the children's names yet.

The coroner said the victims' official cause and manner of death are pending autopsy and toxicology findings.

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A suspect and a missing person's report

Within hours of the family's horrific discovery, police identified Huey as a person of interest, along with a woman he had a relationship with, Burne told reporters during a Wednesday news conference.

The woman was reported by family as a missing or endangered person Tuesday night out of Streamwood, Illinois, Burne said.

Later that evening, Burne said, police issued a statewide bulletin to law enforcement agencies identifying Huey as a suspect in the mass homicide.

Police then issued a bulletin alerting law enforcement Huey was wanted in connection to the killings.

Suspect, person of interest die after Oklahoma car crash

The next morning, on Wednesday, a digital license plate reader alerted the Catoosa Police Department to the suspect's vehicle and a traffic stop was initiated in the city, about 645 miles southwest of where the family was found slain in Romeoville.

The vehicle immediately attempted to flee police, entered Interstate 44 in the city, and ultimately crashed into a concrete barrier, the Oklahoma State Bureau of Investigation (OSBI) reported Wednesday night.

The crash caused the vehicle to catch fire, Romeoville police said in a press release.

At the scene police reported hearing what sounded like two gunshots, and a man believed to be Huey was found dead in the driver's seat. The woman was found with a gunshot wound and was taken to a hospital in critical condition where she later died, OSBI and Catoosa police reported.

Coroner to determine suspect, person of interests cause of death

The agency said the Oklahoma Office of the Chief Medical Examiner plans to positively identify the woman who died after the crash. Police said the office will also determine the couple's official cause and manner of death.

Burne said evidence has shown a nexus between the suspects and the victim as well as a possible motive, but could not comment further as the case remains active and ongoing.

"Although Huey is identified as a suspect, this is still an active and evolving investigation," Romeoville police said. "This portion of the incident is still unfolding. We appreciate the public’s cooperation and assistance."

He did say no other people are suspected of being involved in the family's killing.

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Police say Romeoville, Illinois family murdered in home

Romeoville police said they believe the family members were fatally shot sometime between 9 p.m. Saturday and 5 a.m. Sunday.

The bodies were discovered when the Romeoville police responded to a request for a well-being check at the residence, authorities wrote in a statement.

Police said the check began when one of the family members failed to show up for work at 6 a.m. on Sunday, and did not respond to phone calls throughout the day.

Anyone with information about the case is asked to call Romeoville police at 815-886-7219.

Contributing: Saman Shafiq

Natalie Neysa Alund is a senior correspondent for USA TODAY. Reach her at [email protected] and follow her on X, the platform formerly known as Twitter @nataliealund.