JOLIET, Ill. (CBS)– A murder-suicide in Joliet took the life of a man and his 1 1/2-year-old son this weekend, and has left a tragic mark on the community.

The Kendall County Coroner’s office said 35-year-old Christopher Michael Miller and 18-month-old Colton Michael Miller both were found dead Saturday at a home on the 8300 block of Buckingham Road in Joliet. Autopsies determined both died of multiple gunshot wounds. The father’s wounds were self-inflicted.

As CBS 2’s Jeremy Ross reported, it remained unclear Sunday night what led to the killing of the toddler.

Police said moments before they arrived on scene, neighbors heard the sounds of gunshots.

Before it all, people living nearby said they rarely saw police squads and never saw gun violence in their community – until this weekend.

“We saw the big SWAT machine; the SWAT car come up – the green one,” said witness Lorena Watkins That’s when we knew, like, OK, they’re going to go in.”

On Saturday afternoon, Joliet police made their way to Buckingham Road. Cell phone video showed they prepared for the worst.

“They came with the SWAT; the trucks; they had the drones – all that; ARs,” a man said. “I heard it wasn’t good.”

“We didn’t know if it was going to be a shootout or what,” Watkins said. “It was an unsettling scene.”

Watkins saw and shared cell phone video of the confrontation that police said began with a call of a woman screaming inside a home in the 8300 block of Buckingham Road.

The officer who responded was met with a 32-year-old woman and a 9-year-old girl, both of whom had suffered “fresh” injuries, police said. The officer was told that the sound of gunshots had come from the house moments before he arrived, police said.

The woman said Christopher Miller was her husband, but they were separated, police said. She also said their 1 1/2-year-old baby was in the house with him, police said.

Crisis negotiations were called in, and for hours, police said they tried to reach a peaceful resolution with the Christopher Miller – but eventually chose to break in the front door.

“Police blocked off both sides of the street, and they were reach to go in –they were hiding behind the houses and everything,” Watkins said.

Tire tracks in the front yard and a boarded-up doorway remained Sunday evening. Meanwhile, small stuffed animals and memorial items were placed on the lawn, serving as reminders of the tragic scene law enforcement discovered as they rushed in.

Police said Christopher Miller killed himself, but not before he shot the 1 1/2-year-old boy.

“The baby – he was barely walking,” Watkins said. “It’s just so. It’s heartbreaking. Everyone was crying.”

“To take your own life, that’s one thing, but to take someone else’s,” a man said.

Hours before the police activity, Watkins described Christopher Miller as erratic – but never imagined the outcome would include a SWAT team and such a tragic outcome.

Both female victims were transported to AMITA Health St. Joseph Medical Center Joliet to be treated for their injuries.

The murder-suicide remained under investigation Monday morning.