We Thought We Knew You: A Terrifying True Story of Secrets, Betrayal, Deception, and Murder

Written by M. William Phelps

Narrated by Danny Campbell

In July 2015, Mary Yoder returned home from the chiropractic center that she operated with her husband, Bill, complaining that she felt unwell. Mary, health-conscious and vibrant, was suddenly vomiting, sweating, and weak. Doctors in the ER and ICU were baffled as to the cause of her rapidly progressing illness. Her loved ones—including Bill and their children, Adam, Tamryn, and Liana—gathered in shock to say goodbye.



In the weeks that followed Mary's death, the grief-stricken family received startling news from the medical examiner: Mary had been deliberately poisoned with colchicine. Another bombshell followed when the local sheriff's office received a claim that Adam Yoder had poisoned his mother. But Adam was not the only person of interest in the case.



Pretty and popular Kaitlyn Conley, Adam's ex-girlfriend, worked at the Yoders' clinic. She'd even been at Mary's bedside during those last terrible hours. Still, some spoke of her talent for manipulation and a history of bizarre, rage-fueled behavior against anyone who dared to reject her. Had Kaitlyn and Adam conspired to kill Mary Yoder, or was the killer someone else entirely?



Contains mature themes.

• Language: English
• Publisher: Tantor Media, Inc
• Release date: Dec 29, 2020
• ISBN: 9781705284865

M. William Phelps

Investigative journalist M. William Phelps is the author of I’ll Be Watching You, If Looks Could Kill, Because You Loved Me, Murder in the Heartland, Perfect Poison, Lethal Guardian, Every Move You Make, and Sleep in Heavenly Peace. He has appeared on dozens of national radio and television programs, including Good Morning America, Court TV, The Discovery Channel, Geraldo at Large, and Montel Williams, and has consulted for the Showtime cable television series Dexter. He lives in a small Connecticut farming community with his wife and children.

Reviews for We Thought We Knew You

[mikal sparkman · Rating: 5 out of 5 stars]

I really enjoyed it! Listened pretty much straight through while working around the house. This author has a great storytelling style!

[Julie Boler · Rating: 5 out of 5 stars]

Fascinating story, well told. After you read it take a look at the Dateline episode about! It’s on the NBC website.

[Dani · Rating: 4 out of 5 stars]

Very interesting case, although it does slag a bit in the beginning, it does pick up about halfway through. It is a bit annoying hearing about an extremely codependent relationship that Adam could and should have left so many times but did not and so his mom ended up dead. I do feel like the author left some important things out of the book like the motive to even commit this horrible crime. It is overall however an intriguing story of a toxic relationship taken to the extreme.

[jbertot-838578 · Rating: 5 out of 5 stars]

This author provides you all the facts about the murderer and leaves you to make up your own mind on who the killer is. I am a true crime junkie and I LOVED this book. It's all in the details I always say. Great story line and wonderful presentation. I love the 2023 update the author provided. I Highly recommend to anyone that enjoys a GOOD True crime book.

[amcheri-1 · Rating: 3 out of 5 stars]

I struggled with this book. The case was interesting but it took me a good third of the book to get into it. Honestly, I think the narrator was the problem. His voice just grated on me. I mean, he added some emotion to the reading but I think I would have enjoyed the book much more had I read it with my eyeballs.

I'm a huge fan of true crime books and documentaries but I don't think I'd recommend this one. At least not the audiobook.

Thanks to the publisher and NetGalley for the chance to give an author I'd not heard of a try.

[marquis784-1 · Rating: 5 out of 5 stars]

I received a complimentary print copy of this book from the publisher and Bookish First Impressions in exchange for an unbiased review.

This is the first true crime book I’ve read by this author but won’t be the last. He has a unique manner of presenting all the facts from every perspective. It is obvious that extensive research has been done to write such a compelling book.

As Mark Twain is noted for stating: “Truth is stranger than fiction, but it is because Fiction is obliged to stick to possibilities; Truth isn't.”

Since this is true crime there really are no “spoilers” as the case has been followed and reported by the media outlets. I will add my review regarding my personal comments and opinions.

The author goes to great lengths to make the story about the victim Mary Yoder and not the sensationalized media attention or conspiracy theories. I admire the presentation of the facts and evidence as they are and not what some would like them to be. Just because people “can’t imagine” someone being capable of such heinous acts doesn’t mean she didn’t commit them!

It is obvious that Kaitlyn “Katie” Conley is a person with deep rooted psychological issues. An example of a sociopath with whom we should all take note as there are many people in world just like her. The conniving and manipulative mastermind of those people should not be underscored.

Another appalling aspect was that regarding Dateline and their coverage of the case. I don’t recall whether I watched that episode. The author is respectful but does share information that he received from several reliable sources. As much as we hope that media presentation will be accurate we must always remember that people are human. The human spirit is strong and wants to believe the best of people and shun the possibility of such evil. The most difficult task is to put all feelings aside and examine facts without emotion or judgment. I believe that M William Phelps possess that ability.

[loraineo_8 · Rating: 5 out of 5 stars]

Another great true crime book by M . William Phelps.. Mary and Bill were married for many years and had a chiroprctor business. Mary suddenly became ill and died.. a few weeks after her death it was discovered she'd been poisoned.. Lots of detail and questions about the 'suspects' in the poisoning. A really good. book !

[litwitch-727589 · Rating: 5 out of 5 stars]

I'm a huge fan of anything true crime, so I was excited to receive this one! It's my first book by Phelps and won't be my last.

The murder of Mary Yoder is one I hadn't heard of before reading this. The entire story just left me at a loss of words. How can someone who looks like such a normal, young girl do something as horrific as this?

Phelps did a phenomenal job researching the case. It may seem a little one-sided, but the author does explain why. Phelps tried to get the other side of the story, but Katie's family refused to talk. In my opinion, that's because they know deep in their hearts that Katie is guilty.

(I promise I'm not spoiling anything. This one isn't about figuring out who did it, necessarily. It's all about WHY she did it.)

I noticed some readers didn't like the transition between each chapter or the flashbacks, but I think both are essential to any true crime story.

5 huge stars for this one!!

[gpangel_1 · Rating: 4 out of 5 stars]

We Thought We Knew you: A Terrifying True Story of Secrets, Betrayal, Deception, and Murder by M. William Phelps is a 2020 Kensington publication.

An unreal, twisty, very sad, true crime saga...

This book is about the murder of Mary Yoder, a vibrant, active person, who, along with her husband, Bill, ran a chiropractor clinic.

The couple had hired their son Adam's girlfriend, Kaitlyn Conley, to work in the office, and never allowed the couple's on/off turbulence to affect the work relationship they had with Kaitlyn. In fact, it seemed Mary and Kaitlyn got on quite well... Until one day...

Mary came home from work presenting with symptoms of a violent gastrointestinal illness. The initial consensus was that she had a bug, just as Adam had endured a short time ago, but it soon became clear that Mary needed medical attention.

Once admitted into the hospital, the staff also felt her illness was due to what was most likely a short- lived stomach bug. But, Mary's condition quickly deteriorated, taking a serious turn for the worse. She coded, then rallied several times before finally succumbing to death.

Because it did seem very unusual that a woman in perfect health had died so suddenly, an autopsy was performed, where it was eventually discovered that Mary had been poisoned with colchicine, a substance normally used to treat gout- a condition she did not have.

The investigators, as is usually the case, zeroed in on Bill, but an anonymous letter pointing the finger at Adam changed their focus, leading them to conclude that Adam might be the victim of a frame-up.

Who wrote that letter? Who stood the most to gain from Mary’s death? Did Adam kill his mother… or was there a more sinister plot afoot?

Well, this was one strange story. By all accounts, Mary was a wonderful, beautiful, spirited woman. Why on earth were there SO MANY suspects???

My goodness- Mary’s husband, her son, her friend and employee, Kaitlyn-

They were All primary suspects. Mary’s daughters, and law enforcement say all the evidence points to Kaitlyn, but three of Mary’s sisters think it was Bill, while Adam also faced damning evidence and accusations against him, as well.

What did the jury say? Well, you’ll have to read the book to find out the shocking way this case came to a close!

I have my own opinion, and because of remarks made by the author about the Dateline coverage of the case, I looked it up online. Mary’s daughters had interview time, as did Mary’s sisters. I didn’t really pick up on a strong slant. Still, I was disappointed to learn those involved in the Dateline production, seemed to have favored one side over the other. No matter, though, because I’m still with the author on this one.

This is just a horribly sad case. Mary seemed to live life with gusto, with so much more to give, it's just tragic that her life was cut short in such a cold, ruthless way, and that her death has torn her family apart.

As for the organization and presentation of the facts, the author uses multiple timelines, outlining Adam and Kaitlin’s relationship, Bill and Mary’s history, the gathering of evidence and the trial.

For the most part, this approach works well, and prevents the book from becoming too dry, the way a more traditional, chronological approach might have. The downside to this method is that it led to some repetitiveness.

One should also be aware that this book is focused Kaitlyn, who was the person arrested, and who was placed on trial for Mary's murder.

The book, I think, sets out to remove all doubt about who killed Mary Yoder. From that standpoint, it might seem one sided- but in my personal opinion, the evidence bears the burden and law enforcement got this one right.

Overall, true crime fans will find a great deal to puzzle over with this case. The courtroom drama was unbelievable, and the author lays out his case admirably and convincingly. I hope the Yoder family finds some comfort and peace moving forward.

4 stars

[katehonig · Rating: 3 out of 5 stars]

Thank you to Netgalley and Kensington Books for an ARC of this book in exchange for an honest review.

I really enjoy reading True Crime books when the author focused primarily on the victim and the hole their death left behind instead of spending all their time on the murderer.

Dr. Mary Yoder was poisoned in 2015, but this book doesn't just focus on her murder, we learn about her life, her family, her hobbies and how much she loves her job. She was a gardener, a mother and the type of person who lit up the room. The book never allows us to forget that a whole, unique person was lost when this woman was killed.

Slight spoiler ahead... The book also builds a solid and believable case for the guilt of the woman who was convicted of the murder, Katie Conley. This book outlines the unbelievable twists and turns of this case, and the amazing way technology was used to crack the case.

[shelleyraec · Rating: 3 out of 5 stars]

*WARNING: mild spoilers*

I’m not sure what drew me to request We Thought We Knew You to read, other than it’s been a while since I’ve read a straight true crime focusing on a single case, and the author, William M. Phelps, has been recommended to me previously. Until I read the synopsis, I had never heard of this particular case and knew nothing of the details, or the outcome.

In July of 2015 Mary Yoder, a beloved wife, mother, grandmother, and successful chiropractor in the state of New York, was rushed to hospital after experiencing the sudden onset of severe stomach pains, nausea and breathing difficulties. Despite all attempts to treat her symptoms, Mary’s condition continued to deteriorate, and less than twenty-four hours after falling ill, she was dead. Stunned, her family requested an autopsy be performed, and were shocked to soon learn not only was Mary poisoned by a deadly toxin, Colchicine, but there is suspicion it was deliberately administered.

Drawing on personal interviews, legal documents, and public records, award winning investigative journalist, author, and media presenter William M. Phelps presents a coherent and concise exploration of the life of Mary Yoder, the investigation into her death, and the subsequent trial that saw a young woman, the on-and-off-again girlfriend of Mary’s son and office manager of the family Chiropractor practice, convicted of manslaughter.

I found this to a very readable account of a tragic crime. I appreciate that Phelps does his best to ensure that Mary, by all accounts a warm, vivacious, intelligent and caring lady, is not merely a victim, but a person whose life was as important as her manner of death. He provides adequate context to the crime, exploring the backgrounds of, and relationships between, those intimately involved. The process of the police investigation is clearly laid out, giving insight into how the police gathered evidence and narrowed in on their suspect. The court cases are related in summary, so as not to get bogged down in jargon and detail.

I’m not sure at which point Phelps became convinced of the accused’s guilt, whether it was before or during his investigation into the case but there is a lack of objectivity here that bothered me somewhat. It’s not that I disagree with his conclusions, the evidence presented, presuming it’s accuracy, leaves me in no doubt that Kaitlyn Conley intended to cause the death of Mary Yoder, and frame Adam Yoder, Mary’s son and Katie’s ex-boyfriend, for her murder in what I conclude was a twisted plan of revenge for rejecting her, but that the bias is inescapably pervasive from the first. I would have preferred that Phelps had been able to gain an interview with someone from the defence, though he states all such requests were refused. While he does discuss the rebuttals given by Conley’s supporters, there is an uncomfortable imbalance in what he is able to present.

We Thought We Knew You is a sad tale of a toxic relationship, obsession, betrayal, and murder. Mary Yoder died horribly, a victim of intentional poisoning, yet simply a pawn in a quest for revenge by a remorseless killer. As of this month (December 2020), Conley has launched an appeal against her conviction.

[marple21 · Rating: 4 out of 5 stars]

I haven't read a true crime book in quite a while but I was glad that I picked this book up. From the start it was so interesting to see where it was going and it kept a good speed to keep the reader interested. It seems like the author knows what they are doing and are using the facts that they have to write out what happened.


I also like how this story brought this case to life because I had never heard of it before now. It made me want to look into the case and see what everyone looked like and I think that says a lot for how the book engaged me and made me care for the characters.

The only problem with this book that I had was the fact that sometimes I would get confused. This was because it would jump back in time, mainly to describe Adam and Kates relationship, and I would not realize that it was doing so at first. It seemed easier to determine when it when jump back in Bill and Mary's past then Adam and Kates for some reason.