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The Monster Within: A True Story of Bloodthirst, Brutality and Barbaric Evil

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Prostitutes and animals could no longer satisfy Peter Kürten’s sexual deviancy. During a burglary of a local tavern, he stumbled upon a nine-year-old girl asleep in her bed. He strangled her, slashed her throat with a pocket knife, and orgasmed upon hearing her blood drip to the floor.

His crimes were halted by World War I and an eight-year prison sentence but he unleashed his urges with a spate of brutal murders in 1929 earning him the nickname "The Düsseldorf Monster".

No one was safe. He committed ferocious attacks, sexual assaults and murder against men, women and children. He used blunt objects, sharp implements or his bare hands, before drinking their blood for sexual satisfaction.

The Monster Within is a chilling account of Peter Kurten, one of the most terrifying serial killers in true crime history. Ryan Green’s riveting narrative draws the reader into the real-live horror experienced by the victims and has all the elements of a classic thriller.

This book contains descriptive accounts of abuse, extreme violence and animal cruelty. If you are sensitive to this material, it might be advisable not to read any further.

134 pages, Kindle Edition

Published September 18, 2023

250 people are currently reading
173 people want to read

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Ryan Green

96 books85 followers

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5 stars
206 (47%)
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81 (18%)
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Displaying 1 - 30 of 35 reviews
Profile Image for Julie  Young Buckler .
112 reviews98 followers
November 11, 2023
Talk About Gruesome

Fortunately, this story is rare. I just finished it and I can't believe what I just read. This story is so convoluted and the non-fiction of it all! I had a difficult time putting this book down. The story was neatly written and it's a fast moving narrative.
Profile Image for DancingMarshmallow.
511 reviews
July 31, 2024
Overall: 4 stars.

This is a short-ish, but well written and gruesome account of the case of the Vampire of Dusseldorf. I'd heard of Peter Kurten, true crime nerd that I am, but I didn't know much about him or his crimes until reading this book. And now I have to issue a huge WARNING: this book contains a lot of torture and blood and guts, more than even your typical true crime story. Kurten was a nasty little gremlin of a man, so if you're sensitive to child murder or gore, I'd steer clear and just read the wikipedia if you want the highlights. Dude was fucked up, essentially.

The author does a great job summarizing Kurten's life and crimes and painting a general picture of life in pre-WW1 Germany, and even though I really enjoyed the book, I'm deducting a star because I feel like it glossed over the investigation and arrest. I get the feeling the author wasn't intending to do a super-deep dive into this case, but nevertheless, he mentions in the conclusion about how influential this investigation was in terms of early use of psychiatric profiles, graphology, and other forensic methods, and I would have really loved more information on how the investigators used those fledgling techniques at the time.

Nevertheless, this was an enjoyable - if super gross and horrifying - true crime tale, if you have the stomach for it.
Profile Image for Kathleen Riggs.
599 reviews20 followers
September 18, 2023
Such A Monster Actually Existed.
Once again, another Truly Inspirational Read by Ryan Green. This book is about a man called Peter Kurten who was born in May 1883 in Germany. Peter came from an extremely poor family and lived with his family in a one-bedroom apartment. Peter was the oldest child, and his father spent his days and nights at the local Inn and would come home drunk and beat and rape his wife and beat the children from an exceedingly early age. This of course left Peter as the punching bag as he tried to protect his brothers and sisters from his father's raft.
Peters' perspective on life was different from other children and sadly when Peter was aged nine years old his class went rafting down the river Rhine and Peter kicked one of the boys overboard for no reason except for saying he could not swim. When the other horrified boy saw what happened he yelled out what have you done Peter and he did not hesitate to jump in to save his friend from drowning as he was a confident swimmer. Sadly, both boys drowned.
Peter made his excuse when he came around the corner crying and telling the teachers that one of the boys fell overboard and the other drowned after trying to save him. Nobody suspected Peter a nine-year-old boy of lying let alone murder as he was a good boy in class and the teachers thought they were his school friends. Peter felt nothing for them, but he was excited at the killings, and he had a secret that his drunken brute of a father would never know.
This is the start for Peter who goes on to meet a Neighbour who first sexually abuses Peter and then takes him out and teaches him how to torture and murder animals which Peter finds turn him on when he sees the suffering of the animals but especially when he sees blood, he gets a sexual feeling he has never experienced before. The Neighbour is soon arrested, and Peter decides then not to go home but lives on the streets. Peter gets into Bestiality which progresses on to Peter become a total Psychopath and killing. For years nothing changes Peters predatory and murderous intent which now follows of innocent children, women, and men.
The amount of detail Ryan Green has written is absolutely chilling to read and This book is not for the faint hearted as you will read the haunting accounts of the molestation, rapes, and horrific Violence inflicted on these innocent victims. You will be thoroughly horrified by the monster Peter becomes. This is an exceedingly difficult book to read, and the author Ryan did an excellent job of telling this story and giving you a true feeling of who Peter was. Sadly, for all his poor victims who were abused, tortured, and murdered, their family’s nightmare never ended. A fantastic true crime read which is very graphic and realistic but defiantly worth reading.
I am part of the ARC group for Ryan Green, and I am leaving this review voluntarily.
Profile Image for Chiara Cooper.
515 reviews30 followers
October 19, 2023
Where do I begin? This was a difficult read for me due to the explicit abuse and cruelty on animals. I have read lots of books with violence and abuse but when it comes to animals my heart bleeds.
In addition, there is lots of violence and if you have any triggers at all, I suggest you don't read it as it's not only brutal, but it's based on true facts!

This is the story of sadistic murderer Peter Kürten, also known as The Düsseldorf Monster. The story spans from his troubled and violent childhood through his first try at murder and to his behaviour escalation, never able to satiate his 'urges'. I knew his story and I knew him also through his other nickname The Vampire of Düsseldorf (you guess why) but I didn't know the details or his upbringing and I found this read fascinating and horrific at the same time.

Ryan Green's writing style is very compelling, managing to weave some poetic licence when needed, without appearing unrealistic, with the result that it felt like a novel and not a documentary.

Needless to say this read sparked some internal debate (as it's often the case with serial killers), and the unresolved question of nature vs nurture.. To be honest, whilst his childhood was traumatic, throughout the book he is portrayed as showing knowledge of his actions and recognising his deviances, with a will to live a 'normal' life which he does at some point.

The fact that this book made me question myself yet again about these matters is proof that I did enjoy it and felt totally invested, albeit also horrified for his actions. I felt enraged, disgusted, sad and more than once I pictured myself in the victims' position.

I totally recommend this book to true crime lovers, but be sure to check the trigger warnings.

Thanks to Ryan Green for a copy of the book and this is my honest review.
Profile Image for Kim.
508 reviews5 followers
September 18, 2023
The title says it all…

This detailed examination of the horrific life and crimes of Peter Kürten, historically known as "The Vampire of Düsseldorf" and the "Düsseldorf Monster", gives new meaning to the term cringeworthy. As per usual with any of Mr. Green’s work, the research is thorough and meticulous, and the writing will transport you directly into events as they unfold, but be advised that this book is difficult to read in some places due to the grisly nature of Peter’s depravity. As with so many serial killers, his childhood was horrendous beyond imagining and the abuse he endured undoubtedly contributed to the shocking behavior manifested by Peter from a young age. Given the ghastly treatment he received at the hands of his brutish father, it is little wonder that Peter developed into a vile being of boundless sadistic rage devoid of any moral compass to reign in his gruesome appetites. In Peter’s case, it seems that both nature and nurture conspired against him and the result was catastrophic for anyone crossing his path. Contained within these pages is a riveting account of that train wreck of humanity, at once sickening and compelling. The title says it all.
Profile Image for Deirdre.
1,571 reviews16 followers
October 21, 2023
Since I was a young girl our family always had German shepherds. I studied German in both high school and college. My dogs knew commands in both English and German. Then I went away to college to study my major Criminal Science. Well it didn't take long in my German/ Criminal Science research to come across Peter Kurten, I'm talking 40 years ago. But I never forgot that he was a monster. What Ryan Green superbly did was bring this beast to life in a way I never experienced in college or more recently a podcast.

Peter's deeply disturbing upbringing, his own nature that demonstrated when given a choice between being humane, cruelty always seem to be his go-to. He was an evil abomination in a dapper little suit. His behavior was sickening and perverse. He was seemingly seething with rage. It was shocking how he long he continued to get away with such awful crimes. He terrorized Dusseldorf with his twisted fantasies. He was a savage, a philanderer, and utterly depraved man who made reading this book both fascinating and disturbing. Five stars for Mr Green.
Profile Image for Zelda.
184 reviews5 followers
September 19, 2023
This book had me in it's grip from start to finish. The story did cause me to ponder the theory of nature versus nurture. In Peter's case, I think it was possibly a combination of both, with quite a bit of free will thrown in. The more I read, the lower my jaw dropped. That such a monster actually existed in this world is almost too fantastical to believe. The cruel and disgusting tortures he inflicted on his poor victims, the disgusting ways in which he desecrated their corpses. His total lack of remorse, and not a shred of truly positive human emotions. His monstrous sex drive, which could only be appeased while causing others pain, fear, and blood loss. It is chilling to note that his monstrous traits started from a very young age, and only grew stronger and more warped, the older he got. I highly recommend this book for anyone who enjoys true crime and who has the fortitude to withstand some very graphic descriptions of violence.
Profile Image for Daniel Kupres.
260 reviews
September 18, 2023
German Peter

This monster named Peter from Germany is the first one in a while that made me sick to my stomach. Whether it was the physical and psychological abuse that young Peter went through or the terror that he provided to his victims, there were moments that I had to put the book down and find something uplifting to look at. Set in Germany pre and post WW1, it’s no surprise that he was able to become a serial killer. It actually reminds me of two novels I read about serial killers set in WW2 and if Peter’s story was a basis for it. Ryan tends to pick very unique subjects like Peter and presents much of the story from the eyes of the killer or from the view of the victim but with The Monster Within, he presents to us both sides of the coin when the crime of passion is being committed. Truly disturbing.
Profile Image for Ann237.
427 reviews5 followers
Read
September 19, 2023
Ryan Green has such talent of pulling readers into his True Crime writings standing at the door looking in. WARNING BOOK MAY CAUSE TRIGGERS.
As a fan of true crime & of Ryan Green I can say he truly does his research…With that said, this book was one of the most disturbing, gut-wrenching ones I have ever read. The sexual perversion that "The Düsseldorf Monster" the sadistic serial killer who found short lived pleasure in the killing and sexual acts, yes performed in that order most times. The sound of death & suffering giving him the release he kept chasing had no limits from animals, adults, children if he could rape, kill & get his needs met they were his. The book certainly provided the true crime intensity. I gave the book 5 stars for the Authors ability to take us on a journey with his research & the putting of words together of the unimaginable.

Profile Image for Carlee.
21 reviews
December 29, 2023
nightmare to imagine the depravity

For anyone interested in forensic psychology, this book explains the depths of early childhood trauma. The details are difficult to read due to the innocent victims involved in such heinous acts of violence. This book also establishes the importance of interviewing and delving into the mind of such monsters. Many of the “markers” that are evident in psychopaths at a young age are clearly defined in this case. It is interesting that so many of those markers are prevalent in modern day serial killers that it has become a scientific identifying field for detectives. Unraveling the mysteries of the human psyche is a fascinating and daunting challenge. Thank goodness for the woman who made a mistake in addressing a letter and a detective who sought to end the reign of terror.
Profile Image for Cat B..
800 reviews7 followers
September 18, 2023
Another chilling telling of a monster that walked on two legs. Who knows what would become of Peter Kurten if he had been born to a loving father and strong mother. He was charming, good looking, and intelligent. He could have become quite successful, one would think. But he wasn't and he didn't. Instead he became the "Vampire of Dusseldorf", a monster. Ryan Green again leads us through the darkest depths of a depraved mind, and does it well. The writing is such that you easily find yourself there, a voyeur, to the terrible debasement and murders of human beings. Terrible story seemlessly told.
I received a free copy of this book and am voluntarily leaving my honest opinion of the tale.
Profile Image for Tam.
2,179 reviews54 followers
November 11, 2023
This was: ONE OF THE BEST BOOKS I HAVE READ THIS YEAR!!! I wish I could give it more than 5 stars! This was a twisted, fast-paced, interesting read, that I found I did not want to put down! It had well-developed, multi-faceted characters. It was suspenseful, thrilling and addictive! The tension kept my heart beating wildly with anticipation and, sometimes, even fear! I was glued to my Kindle screen from the first page to the last. If you like unputdownable psychological suspense as much as I do, you CANNOT miss out on reading this book!!!

*I received a complimentary ARC of this book in order to read and provide a voluntary, unbiased and honest review, should I choose to do so.
Profile Image for Linda.
1,376 reviews14 followers
September 22, 2023
Another well researched, well written story about a true monster. Peter Kurten learned violence and abuse at an early age and as he grew up, his true identity revealed itself. This is a story that you have to prepare yourself before you start because when I was reading about what Kurten's victims endured before they died, had my stomach churning. Ryan Green has the unique ability to tell these horror stories about true monsters and tell them in a way that brings the crimes to light. I would highly recommend it. I received an advance copy of this book and this is my honest review.
Profile Image for Cheyenne Lacanlale.
126 reviews
October 20, 2023
💀💀BOOOOOK REVIEW💀💀
I LOVE #truecrime BUT it is not for everyone. You cannot have the faint of heart because the stories are true and they are very horrific to think about. @ryangreen is one of my favorite, true crime authors. This was a masterpiece of what childhood violence leads to. If I say anymore, I will give it away. It was worth the read. 🖤🖤🖤🖤🖤

#trucrime #truecrimecommunity #ryangreenauthor #monsters #childhoodtrauma #booksta #booknerdsunite #bookmom #bookmoms #bookmomsgonewild #faintofheart
Profile Image for Joanne.
444 reviews6 followers
November 13, 2023
Peter Kurten has to have been one of the evil men ever born. He grew up seeing his father consistently rape and abuse his mother. He was also abused by his father, as well as his 12 siblings. Growing up the way he did, I guess it makes sense that he didn't really know anything different. Although he tried to change his horrible ways, I guess he didn't really try hard enough.
This was well written and well researched.

This review was written for LibraryThing Early Reviewers.
4 reviews
January 22, 2024
Different for me

I usually read biographies, history, that kind of thing. Not sure how I came across this one but I liked it. Gotta say it was more than creepy though. Coming from someone who has never been in to reading anything like this.
Also my husband is German and we go there every year to visit his family and it's interesting being in places mentioned in this book and again, that's also a little creepy.
Profile Image for Erinn Jarvis-McMahon.
27 reviews
October 3, 2025
This wasn’t a pleasant read by any means because of the horrific subject matter, but it was certainly interesting and informative. Ryan Green dives into the life and crimes of Peter Kürten, the so-called “Vampire of Düsseldorf,” and the detail makes for both a disturbing and fascinating account. While it was uncomfortable to read at times, I appreciated learning more about this case and the darkness behind one of history’s most notorious killers.
52 reviews
Read
January 3, 2026
I have read a few dozen true crime books over the years, but none of the serial killers I’ve read about have been as grotesque and gruesome as this man. It is absolutely abhorrent what he was capable of doing to others. I wouldn’t normally tell someone to give pause before reading a book. However, this book is the exception to that. Go into this book, knowing that your mind will be pushed to some of its deepest limits.
Profile Image for Cece Reads a lot.
52 reviews1 follower
October 22, 2023
I have read just about all of Ryan Greens books but as someone else mentioned this is one of his most disturbing ones. There's a lot of bestiality, incest, rape and gruesome details of killing that often made my stomach churn. Peter kurnst was just pure evil. He had no regard to human nor animal life.
25 reviews3 followers
October 23, 2023
Mad man is too good a label for. Him. Monster is very apt.

This story was horrific. At best I could only read a little at a time because of the atrocities committed. Therefore it took me quite a while to finish the book. Peter was a true psychopath. Hopefully there is no more like him in our world.

Profile Image for Charlie Bray.
49 reviews
March 27, 2024
This man is the most depraved serial killer I have ever read about. The opening chapter had me gripped in fear and hope whilst desperately gasping for breath. Some scenes in this book are quite graphic, so fair warning, most other authors gloss over these details so despite being familiar with the number of lives he claimed the MO and "motive" is not sugarcoated.
Profile Image for Northawke.
155 reviews1 follower
October 12, 2025
Interesting to read about the Vampire of Dusseldorf, but Green takes too many liberties in writing the death scenes, making them almost come across as fictional. There seems to be a decent basis in research, but I urge any non-fiction writers to list their sources and to use footnotes. I deducted a star for that massive failing here.
2 reviews
October 4, 2023
It's a great read

Truly paints a portrait of a psychopath in the making. This book goes into how Peter Kürten grew up and the evil he became. There is graphic details in this book. I have to say Ryan Green put this book together nicely.
218 reviews2 followers
August 3, 2025
Wow!

This book is unbelievable but is absolutely true. One of the most terrifying true crime books I have ever read, and I have read hundreds of true crime books. It will give you the chills!
Profile Image for Clive Willcocks.
292 reviews2 followers
September 19, 2023
Another great read from Ryan. As always well researched and told. Once started I had to finish it. If you like true crime stories, then you'll love this. Highly recommended.
Profile Image for carol finan.
2 reviews
September 24, 2023
Graphic

This book was very graphic. There were some parts so disturbing I had to out the book down and take a break for a while.
11 reviews
October 3, 2023
Another grisly read

I couldn't put this book down a really good gruesome read, I had no idea that mankind could be so violent evil or sadistic . What a totally selfish man he was
Profile Image for Susie L..
Author 1 book4 followers
December 17, 2023
A hard read but well done

Very interesting, yet disturbing, story. Well written although hard to read due to the graphic nature of the criminal acts.
Displaying 1 - 30 of 35 reviews

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