New York Chiropractor Is Poisoned, Leading to "Dramatic" Court Decision: "We Just Want the Truth"
When Mary Yoder, a seemingly healthy chiropractor originally from Buffalo, New York, tragically died at the age of 60, her grief-stricken family was left grasping for answers.
When Mary Yoder, a seemingly healthy chiropractor originally from Buffalo, New York, tragically died in 2015 at the age of 60, her grief-stricken family was left grasping for answers.
The mysterious case took an even darker turn when Mary’s family learned that she’d been poisoned and an unlikely suspect emerged.
Now, nearly 10 years after Mary's death, Dateline is taking a fresh look at the case after a shocking courtroom development has called everything about the case into question. The episode, titled “Poison Twist," will air on Friday, March 21 at 9/8c p.m. on NBC.
As the episode's official synopsis states: "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."
What happened to Mary Yoder?
The once-vibrant Mary’s health took a sudden turn in July of 2015. She was rushed to the hospital, but her life continued to hang in the balance.
“Every time they would revive her, she would be responsive again,” Mary's daughter Tamaryn Yoder told Dateline, as heard in a preview of the episode.
With no obvious reason for Mary’s sudden decline, doctors rushed to unravel the medical mystery.
“They brought in so many specialists,” Mary's sister Janine King told Dateline. “They just couldn’t figure out what was wrong.”
But the efforts of medical professionals wouldn’t be enough to save her and on July 22, 2015, Mary died. Her family was left scrambling for answers, and their anguish multiplied after learning that the beloved chiropractor had been poisoned.
"Healthy people don't just drop dead"
“Sixty-year-old healthy people don’t just drop dead,” Mary’s sister Sharon Anne Mills said on Dateline, while Tamaryn added that the death “made no sense at all.”
Mary’s eldest daughter Liana Hedge tearfully revealed in the episode what she went through at the time. "You feel like somebody dropped you in the middle of hell, and you can’t find your way out," Hedge said.
A suspect comes into focus
Detectives soon turned their focus to an unexpected suspect, Kaitlyn Conley, a young woman who not only worked at Mary’s Whitesboro, New York, practice but had also dated her son, according to Syracruse.com.
“They’re interrogating her for murder. ... something’s wrong here,” Kaitlyn’s father Vin Conley recalled to Dateline of what he was thinking at the time.
Kaitlyn was tried twice for second-degree murder for the poisoning death of her boss, Mary. After a first trial ended in a hung jury, Kaitlyn was convicted of manslaughter in 2017, but the verdict was overturned in January of 2025 in a stunning state appellate court decision.
Mary Yoder's family still searching for answers
Even some people within Mary’’s own family had questioned the initial verdict.
Some family members once told authorities, "She may be being framed," King said.
Mary's daughter Tamaryn told Dateline, “They’ve never sat down and listened to the evidence.”
Dateline sat down with Kaitlyn herself for an update to the two-hour broadcast and also interviewed Kaitlyn's attorney Melissa Swartz about the latest in the case.
“It’s hard to know that I’m innocent and still feel like people want me to be guilty,” Kaitlyn told Dateline.
She added, "There’s so much more going on than people are aware of.”
As the mysterious case continues to haunt Mary's family years after her death, they're just hoping to find out once and for all who is responsible for taking the chiropractor’s life.
“We just want the truth,” Hedge said.
To find out more about the shocking twists and turns in the case, watch Dateline on Friday, March 21 at 9/8c p.m. on NBC or stream the episode on Peacock when it becomes available the next day.
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