Mary Yoder's murder: A complete timeline of events ahead of Dateline on NBC

Mary Yoder was a 60-year-old chiropractor from New York, who died due to cardiac arrest on July 22, 2015. Mary ran a successful business named Chiropractic Family Care. After lunch, she started feeling sick and struggled to complete her meetings.

In the evening, Mary was admitted to the hospital. After suffering from cardiac arrest, Yonder died two days later. When her body was taken for autopsy, medical practitioners were shocked to find out that she had been poisoned.

Dateline's new episode titled Poison Twist follows the complete investigation behind the murder of Mary Yoder. The episode was released on March 21, 2025. The official synopsis of Poison Twist reads,

"The unexplained death of a beloved chiropractor becomes a criminal investigation when authorities discover she'd been poisoned; nearly a decade after the murder, a court makes a dramatic decision about the young woman at the heart of the case."

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What caused the death of Mary Yoder?

Mary Yoder died due to colchicine poisoning (Image via Pexels)

As per a People article, the autopsy reports of March Yoder revealed that she died of colchicine poisoning. When detectives started the investigation, they suspected that Mary was poised through her daily protein drink.

Yonder was popular among her friends and colleagues for maintaining a healthy lifestyle. Reportedly, she also ran a vitamin business on the side. As reported by People, Mary's autopsy reports showed that her internal organs were poisoned with agricultural-grade Colchicine.

Investigators received an anonymous letter that indicated the murder was committed by the victim's son (Image via Pexels)

Soon a homicide investigation was initiated. Initially, detectives started to suspect Mary's husband William to be the culprit. As reported by People, William had started dating Mary's older sister Kathleen, right after her death.

Authorities suspected that William was after Mary's money from the life insurance. The investigators received an anonymous letter, which claimed that Mary's son Adam had committed the crime. The letter also claimed that Adam had Colchicine in his car, which the police found out.

The investigation into the letter revealed that it was written by Adam's girlfriend Kaitlyn Conley.

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The investigation on Kaitlyn Conley

Investigators discovered that the anonymous letter was written by Kaitlyn Conley (Image via Pexels)

Kaitlyn and Adam first met in 2011, at a high school graduation party. The two had an abusive relationship. As reported by Observer Dispatch, Kaitlyn revealed during her trial that Adam had r*ped and choked her on July 26, 2014.

As per an ABC News article, published on September 20, 2024, Conley worked as the office manager for Mary's Chiropractic Family Care. As per People, during the investigation detectives found that Mary had made two purchases of Colchicine from her office computer.

Additionally, it was found that Mary's bottle had the DNA of Conley, which indicated that she may have poisoned her. Soon Kaitlyn Conley was arrested for the murder of Mary Yoder. As per Spectrum News, during Mary's trial in 2017, Adam presented Kaitlyn's search history which revealed she was looking for toxic substances and was reading about Colchicine poisoning.

DNA evidence revealed that Kaityln Conley was responsible for the poisoning (Image via Pexels)

As per Spectrum News, Assistant District Attorney Laurie Lisi revealed that one of the reasons for the murder was to get her revenge on Adam and create a traumatic event in his life. It was on November 16, 2017, when Conley was found guilty of the first-degree murder of Mary Yoder.

Kaitlyn Conley was sentenced to 23 years in prison. People reported that Conley is currently incarcerated in the Bedford Hills Correctional Facility in New York. She will be eligible for parole the next time in 2037.

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