A male delivery driver is being identified as the person stabbed to death Wednesday morning at the Chick-fil-A restaurant at 2740 U.S. Route 34 in Oswego.

A second victim, a male construction worker, sustained serious injuries and was transported to a hospital for treatment, according to a news release from the Oswego Police Department.

The suspect, an adult male, has been taken into custody. Police are still investigating a motive for the attacks and are working with the Kendall County State’s Attorney’s Office to determine criminal charges.

At approximately 5 a.m. Oswego Police were called to the Chick-fil-A restaurant for a report of a stabbing.

Officers arrived on the scene within four minutes of being dispatched and took the offender into custody, police said.

Officers immediately began administering medical aid to the injured victim until members of the Oswego Fire Protection District arrived on the scene, police said.

That victim was taken to a hospital for treatment. Officers conducted a protective sweep of the restaurant and located a second victim, who was unresponsive and was pronounced deceased at the scene, police said.

The victim’s identity is being withheld pending formal identification by the Kendall County Coroner’s Office.

A preliminary investigation indicates that the offender first attacked the delivery driver inside the restaurant at approximately 3:10 a.m. based on restaurant video surveillance timestamps, according to police.

The delivery driver was inside the restaurant when it is believed the offender broke through the back door to gain entry, police said.

Once inside, the offender attacked the victim and killed him.

The second victim was a contracted maintenance worker who was outside the restaurant when the offender attacked him at approximately 4:56 a.m, according to police.

A witness who observed the attack called police and together with the victim subdued the offender until police arrived. The witness was not injured.

“We are grateful for the actions of these two individuals, whose efforts to restrain the offender and call police directly led to the offender’s capture,” Oswego police said in the release.

As a precautionary measure, unclaimed property that was located close to the scene was inspected by the Kane County Bomb Squad which determined there was no threat to public safety. The Kendall County Major Crimes Task Force was activated to assist with the investigation and processing of the scene.

The Kendall County Coroner’s Office also responded to the scene.

Oswego police plan to release further information when it becomes available.