Man accused of killing doctor in front of their 3-year-old daughter in Barrington

BARRINGTON, Ill. (CBS) — A man has been charged with murder in a shooting that killed a doctor in Barrington this past weekend.
William Zientek, 46, stands charged with first-degree murder in the shooting that killed Dr. Olga Duchon. 
Duchon, 42, a well-respected endrocrinologist, was the featured speaker at a discussion with members of the Ukrainian Medical Association on weight loss medication not long before she was killed. 
At Zientek’s first court appearance on Wednesday, prosecutors said he killed Duchon front of their 3-year-old daughter.
Investigators used the camera on Duchon’s Tesla to track her movements that day.
Prosecutors said Zientek lured Duchon, his ex-girlfriend, to his home in Barrington on Sunday on the grounds of having a face-to-face talk. Instead, once she was inside, he allegedly hit Duchon in the head with a baseball bat, fracturing her skull.
Zientek then allegedly shot Duchon in the chest. Prosecutors said he called police and admitted killing Duchon. His defense attorney said Zientek killed Duchon in self-defense, claiming she had a gun.
The gun used to kill Duchon was a weapon Zientek had reported stolen more than three years ago, according to prosecutors.
In court, the judge assigned to Zientek’s case said his relationship with Duchon ended in 2021, and Duchon worked to get his guns taken away.
Duchon – who had a medical practice in Mundelein, specializing in internal medicine, endocrinology, and obesity medicine – had been fighting in court to keep Zientek away from her before he allegedly killed her.
Court records show Duchon filed for an order of protection in November 2021, saying Zientek had left multiple guns “spread all over the house,” in particular on the couch, where he had been dressing their daughter.
In her petition for that protective order, Duchon said, “the reason that I need this order of protection is that I am scared for my life, my daughter’s life, and my parents’, my sister’s well-being.”
She also said Zientek had threatened to kill her and then himself if she left him or cheated on him.
In December 2021, she obtained the second of two orders of protection against him, saying he should have no communication with Duchon, and stay at least 200 feet away from her at all times.
Four days later, an agreed order was entered, indicating Duchon and Zientek were “in agreement to resolve matters without further litigation.”
In June 2022, Duchon and Zientek entered into an allocation of parental responsibilities and parenting plan, when their daughter was 18 months old.
At the time, it was decided, “The maximum involvement and cooperation of each parent regarding the physical, mental, moral and emotional well-being of the child is in the best interests of the child,” and both parents were to work together to that end.
At his first court appearance on the murder charges, a judge ordered Zientek held in jail while he awaits trial. He also may not have any contact with members of Duchon’s family, including his own child. He’s due back in court next month.