Ex-boyfriend shot and killed Dr. Olga Duchon in front of their daughter in Barrington: court docs

Grisly new details were revealed in court Wednesday regarding the murder of a woman in Barrington on Sunday during a fatal encounter with her ex-boyfriend.

BARRINGTON, Ill. - Grisly new details were revealed in court Wednesday regarding the murder of a woman in Barrington on Sunday during a fatal encounter with her ex-boyfriend.

The victim, Dr. Olga Duchon, was found dead around 5:30 a.m. in the home of 46-year-old William Zientek, with whom she shared a 3-year-old daughter, following a violent assault involving a baseball bat and a fatal gunshot wound.

According to prosecutors, the pair had a tumultuous history, with their relationship ending in 2021 over Duchon’s objections to Zientek’s gun ownership. Duchon obtained an order of protection at that time, revoking Zientek’s FOID card and requiring him to surrender his weapons. The firearm used in the murder had been reported stolen by Zientek in 2021.

The Deadly Attack

On the evening of Nov.17, Duchon drove to Zientek’s home, at 406 W. Russell St., after he requested to meet with her. Surveillance video from Duchon’s Tesla showed her arriving at 5:18 p.m., carrying a tote bag containing leftovers and baked goods.

Once inside, Zientek struck Duchon in the head twice with a baseball bat before fatally shooting her in the stomach in front of their 3-year-old daughter, prosecutors said.

Authorities responded to a 911 call from Zientek at 5:33 p.m., finding Duchon unresponsive with a child’s blanket covering her body, court documents said. Evidence recovered from the scene included a 9mm handgun, a spent cartridge casing, a bloodied baseball bat and a backpack containing ammunition and an empty holster, according to court documents.

Dr. Olga Duchon

Investigation

Preliminary autopsy results confirmed that Duchon suffered a fractured skull, a gunshot wound that damaged her liver, heart, and aorta, and significant bruising and lacerations consistent with blunt force trauma. The Lake County Coroner's Officer ruled Duchon's death a homicide by gunshot wound.

Investigators noted that Duchon had dinner plans that evening, with data from her Apple Watch showing her heartbeat ceased at 5:25 p.m., eight minutes before Zientek’s 911 call.

Zientek claimed self-defense, but authorities reported no evidence to support this assertion, prosecutors said. Duchon’s tote bag contained no weapons, only food items.

Zientek remains in custody as the investigation continues.

If convicted, Zientek faces life in prison.