Police were investigating the shooting death of two brothers in Swansea on Saturday night.
At about 9 p.m., a woman came home to find her two adult sons dead at 3921 Whitfield Drive, according to Swansea police. One of the sons had a firearm in his hand.
Chief Steven Johnson said they believe one of the men, 48-year-old Thomas I. Stines, killed his brother, 43-year-old David M. Stines, before shooting himself.
"The totality of the preliminary investigation is showing that this is a murder-suicide between these two brothers," Johnson said.
Both men lived at the house with the mother, Delores "Dee" Stines.
According to court records, in 2012, David Stines was convicted of possession of an illegal substance, domestic battery and driving under the influence while his license was revoked or suspended.
He was sentenced to five years, six months and discharged for parole Feb. 2.
Less than 24 hours after the Stines brothers died, neighbors walked their dogs and talked on the sidewalk on the sunny Sunday afternoon, many of them discussing what they called a shocking event for the quiet neighborhood.
Marcia Altepeter, who lives nearby on Green Haven Drive, said she often saw the brothers' mother walking her dog or working in her yard.
"There's no crime or any events like this here. People get along. They keep to themselves, but they're kind to each other," she said.
Altepeter said she never saw Delores Stines' sons at the house.
Neighbors Judy and Bob Heininger, who have know the Stines for 17 years, said Thomas Stines got a divorce a few years back and had three kids. He had moved back in with his mother, and she was trying to help him get back on his feet.
"She is such a loving mother and was looking out for her sons, it's such a loss to her," Judy Heininger said. "It's such a tragedy for the whole neighborhood."
The Heiningers said the Stines' mother prepared the house earlier that month for David Stines to return home from his prison sentence. She was trying to help both her sons through tough times, they said.
"It's just such a loss for her," Judy Heininger said.
Autopsies of the men were being conducted Sunday and Swansea detectives, Illinois State Police Crime Scene and the St. Clair County coroner’s office continued to investigate.
"The preliminary investigation appears to show this is a tragic murder/suicide within a family," Johnson said in a press release. "Our sincerest condolences go out to the entire family. These types of incidents are never easy to understand why they happened and we may never have an explainable answer. Our investigation is continuing and if anyone had contact with either person on 02-24-18 or know anything about this, we are asking you to call Swansea Detective Gary Reuter at 618-233-8114."