Police said Tuesday morning they believe an Oak Forest father strangled his wife and autistic son before taking his own life.
It appears David Joost, 54, killed his autistic son, Daniel Joost, 18, and wife, Margaret O’Leary-Joost, 55, then went into the garage at the family home in the 6600 block of Courtney Drive where he slit his wrists, tried to hang himself and left an automobile running, Oak Forest Police Chief Greg Anderson said during a brief phone conversation Tuesday morning.
“Our confidence is high that this was a double murder and suicide,” Oak Forest Police Chief Greg Anderson said.
Police, who were called to perform a well-being check at the home at 7:57 p.m. Monday night, forced their way in and found David Joost’s body in the garage, police said. His wife and son were found in their beds.
Autopsies Tuesday revealed that both the wife and son died of asphyxiation, with a secondary cause of death for O’Leary-Joost listed as probable strangulation and smothering, and a secondary cause of death for her son listed as ligature strangulation, according to the Cook County medical examiner’s office. Both of their deaths were ruled homicides.
An autopsy on David Joost ruled that he also died of asphyxiation due to hanging, with incised wounds of his wrists listed as a secondary cause, the medical examiner’s office said. His death was ruled a suicide.
At the time of his death, David Joost was struggling financially due to a loss of employment, police said. Joost’s son, Daniel Joost, was autistic and attended a nearby transition program through the South West Cooperative. Margaret O’Leary Joost worked at Advocate Christ Medical Center in Oak Lawn as a crisis worker.
The couple’s 20-year-old daughter attends Millikin University in Decatur, police said.
The first officers on the scene Monday evening spoke to one of O’Leary-Joost’s co-workers, who told them she had gone to the home after O’Leary-Joost had called into work sick on Friday and failed to come to work again Monday, police said.
The co-worker showed police what appeared to be blood that was coming from the overhead garage door, at which point an officer forced entry and found all three bodies, police said.
Oak Forest Police and the Illinois State Police Crime Scene Unit worked through the night to determine what happened.