Jump to ratings and reviews
Rate this book

Without Mercy: The Shocking True Story of a Doctor Who Murdered

Rate this book
Dr. John Kappler was a well-respected physician in dozens of California hospitals, yet none of his patients ever imagined that his real profession was murder…


The horror began the day he secretly attempted to kill three patients--including a pregnant woman who suffered permanent brain damage at his evil hands. Then, in a driving rampage, Kappler rammed another car, stole it, and used it as a lethal weapon. Yet, incredibly, his fellow doctors bailed him out of jail, and he was soon back on the job.


Desperate to satisfy his lust for killing, Kappler cruelly plunged a patient into cardiac arrest. Next, he pulled the plug on a defenseless man unconscious in a hospital bed. Still, no one stopped him. Finally, he exploded in a terrifying rage of violence and murder. Pressing the accelerator of his car to the floor, he cut down a promising young doctor and seconds later maimed a toddler's mom for life.

256 pages, Mass Market Paperback

First published January 1, 1996

113 people are currently reading
188 people want to read

About the author

Keith Ablow

27 books178 followers
Keith Russell Ablow is an American psychiatrist, New York Times best-selling author, and television personality.

Ratings & Reviews

What do you think?
Rate this book

Friends & Following

Create a free account to discover what your friends think of this book!

Community Reviews

5 stars
54 (23%)
4 stars
56 (23%)
3 stars
81 (34%)
2 stars
31 (13%)
1 star
12 (5%)
Displaying 1 - 18 of 18 reviews
Profile Image for Ruth Turner.
408 reviews124 followers
August 24, 2014

"This is an unsettling story of how an unstable physician committed harmful acts against his patients and had them covered up by his colleagues and nurse-wife."

A quick read, interesting and well written. I had to Google the case after I finished the book, to discover the ending.
Profile Image for Crystal M.
120 reviews6 followers
November 2, 2022
1.5⭐️

This book is very strange and it’s hard to get a read for the perspective that the author has on the crime. It is written by a friend and colleague of one of the victims. It covers the life and crimes of a doctor (dr kappler) who seems to be psychotic. The psychosis makes him hear voices which tell him to hurt, maim and kill people - usually patients. Dr kapplers wife knows he’s psychotic and does everything She can to hide it, she even medicated him at home herself (she’s a psychiatrist) when ever he has a psychotic break until he’s back to normal but doesn’t keep him on antipsychotics permanently which always results in him having another break. The author seems angry at times that so many things happened that could and should have been reported that could have prevented later events from taking place. However about 80 pages in he admits that while researching this book he heard all kinds of stories of medical malpractice and physicians who were under the influence while on the job and that he himself knows of more than one physician who should have been reported - some who are still practicing - and yet he admits he never reports them. I just find it strange that you would write a book expressing how upset you are about your friends murder and how preventable it was while also not reporting physicians who are doing similar things that put patients at risk. How many injuries/deaths could the author himself have prevented had he reported those who he knew were doing things that put others at risk? This book is the definition of the pot calling the kettle black. This book does include a very interesting trial because the jury must decide weather the defendant was guilty or not guilty by reason of insanity in a state in which jurors are allowed to disregard the testimony of experts. I believe he was guilty. I believe he was psychotic but not to the point that he couldn’t conform his conduct to the requirements of the law and certainly not to the point that he didn’t know right from wrong.
282 reviews
December 8, 2024
You can also see this review, along with others I have written, at Mr. Book's Book Reviews.

Mr. Book just finished Without Mercy: The Shocking True Story Of A Doctor Who Murdered, by Keith Ablow.

This book was published in 2010.

This is a short book on Dr. John Kappler, who was convicted on murder charges. He was an anesthesiologist who suffered from mental problems. His mental illness led to him trying to kill patients in the hospital before he went and killed someone and attempted to kill another victim. Despite the mental illness, the jury found that he did show the ability to ignore the voices in his head when it was in his own interest and the crime involved enough planning to be a voluntary act.

While the book was interesting, there wasn’t anything in it to make it stand out. So, I give this book a B.

Goodreads requires grades on a 1-5 star system. In my personal conversion system, a B equates to 3 stars. (A or A+: 5 stars, B+: 4 stars, B: 3 stars, C: 2 stars, D or F: 1 star).

This review has been posted at Mr. Book’s Book Reviews and Goodreads.

Mr. Book finished reading this on December 8, 2024.
Profile Image for Lori.
388 reviews
January 11, 2025
Didn't Care For It

I found this book to be a strange one. First thing I will say is that it didn't hold my attention even though I kept hoping it would get better as the story progressed. Maybe it's just me...
The subject of the book, Dr John Kappler isn't even likeable! You know how the experts and others will often say that these types of people can often be very charming as a way to blend in, throw people off and attract a potential victim? This guy was not like that in my opinion. Both the doctor and his wife Tommie seem almost devoid of feeling. She was supposedly a psychiatric nurse and yet she hid her husband's symptoms, allowed him to drive and work knowing he was self reporting hearing voices. She too just seemed emotionally absent as well as irresponsible.
This lack of emotion made the book difficult -- as did the fact that the so called psychiatric experts couldn't seem to agree on diagnoses nor did any seem to put much effort into breaking down his defenses.
Sometimes repetitive and not enough emotion or detail where it counted.
Profile Image for Mishon.
456 reviews2 followers
January 2, 2024
I was relieved when I read the jury’s decisions. And I think Tommie is criminally to blame too. For example, when Kappler injected a patient with a lethal dose of something and then that patient was resuscitated and ended up okay, she said about the situation “nothing happened to the patient. there was no problem. It was just something he did” she continually covered up for her husband and hid things.
Just the thought that he could have gotten away with an insanity verdict angers me.
I’m assuming Kappler has since passed away, hopefully it was in prison.
This entire review has been hidden because of spoilers.
Profile Image for Mackenzie.
176 reviews1 follower
December 13, 2024
I was so confused whether he was actually suffering from psychosis or if he was faking it. The author never reveals that to you. He himself doesn’t know.

Honestly this was just annoying because all of Kapplers symptoms seemed fabricated. He would tell someone one thing and then tell another person something completely different. He even told investigators how he had rationalized hitting two people with his car. Now how is that not premeditated?
Profile Image for Mars G..
346 reviews
October 11, 2019
When it comes to true crime, I'm quite a fan. I'm even more of a fan of a book written with an introspective tone and this one certainly impresses. If you're looking for a look into the human psyche in a really well-done way and a sympathetic view into someone who has murdered - perhaps caused by mental illness, perhaps not - this is definitely worth the read.
250 reviews2 followers
September 5, 2024
Without Mercy

This book was written in mainly medical terminology. Most of the second hand information gained from former Doctors and other medical staff makes much of the information difficult to understand. The back and forth of time periods can be confusing at times. A lot of research went into this book but if you have no medical knowledge it might be hard to keep up with.
Profile Image for Loraine.
480 reviews
September 16, 2024
Dr. Kappler was convicted of murder and attempted murder in the assaults on Paul Mendelsohn and Deborah Brunet-Tuttle and is now serving a mandatory life sentence. In the view of the jury, he was legally sane; or, as Keith Russell Ablow remarks, his "brand of madness was outside the bounds of the insanity defense." In my opinion he is a sick man and should be held in a psychiatric hospital.
Profile Image for Sissy Johnson.
438 reviews9 followers
May 27, 2024
Overall, this is a good book. However, I wish we could have heard from the doctor himself. I feel like getting all the information secondhand really didn't give the reader true insight into the mindset of the doctor. But again, overall, it is a good true crime book.
168 reviews
October 2, 2024
Was expecting an Ann Rule type of book. This one was boring.
11 reviews
October 11, 2024
Required headline

Very sorry to have purchased and read this book When they made the word fluff They had not read the story yet
15 reviews
November 8, 2024
Rivoting

Could not put this book down. I changed my mind on the verdict so many times but agreed with the verdict given
Profile Image for Marilyn.
5 reviews
January 8, 2026
Engrossing

Well documented true story and a real page turner. You won’t be disappointed by the results of this interesting book
Profile Image for Paula.
134 reviews8 followers
October 6, 2011
I really like this book so far. Keith Ablow--probably because he is a psychologist or something like that--delves deeply into his characters, and this isn't always the case with true crime books. Finished it! Nice book.
Profile Image for Michael.
254 reviews5 followers
September 8, 2024
Read this book back in November 15, 2003. What I can remember of this book was that it was a good read that kept my interest until the end.
670 reviews13 followers
March 5, 2016
I believed I read it a couple of months ago, but I couldn't recall the story at all, apart from the beginning. So it must be so-so :-)
Displaying 1 - 18 of 18 reviews

Can't find what you're looking for?

Get help and learn more about the design.