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The poison
It was a vicious, calculated murder using the deadly toxin aconite.

The victim
Rich and powerful, John Weston had plenty of enemies, but DS Mackinnon and the Major Investigation Team have to find out who hated him enough to subject him to such an excruciating death.

The suspects
Even when the source of the poison has been tracked down to a laboratory at the University of Oxford, the deadly threat remains. The staff and students at the university all seem to have something to hide.

The arrest
After an arrest is made, his colleagues believe the case is all but closed but Mackinnon's nightmare is only just beginning.

(This book was the first book written in this series. However, the author wrote a prequel and they have been renumbered.)

432 pages, Kindle Edition

First published March 7, 2012

1490 people are currently reading
327 people want to read

About the author

D.S. Butler

35 books903 followers
Author of the Karen Hart series. Ex-biochemist turned crime-writer. Huge Queen fan. Loves to read crime fiction.

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5 stars
1,263 (34%)
4 stars
1,377 (37%)
3 stars
832 (22%)
2 stars
185 (4%)
1 star
57 (1%)
Displaying 1 - 30 of 61 reviews
Profile Image for Gary.
3,045 reviews425 followers
March 10, 2021
This is the 2nd book in the series and following the fairly slow start of book 1 I am suddenly starting to enjoy this series. I enjoy this authors writing and purchased the first three books in this series hoping for another great series off her. Well all of a sudden it looks like I could have another enjoyable book series on my list.

A man is found poisoned by the deadly toxin aconite and the note found at the scene leads Detective Sergeant Jack Mackinnon to a University of Oxford laboratory. The staff and students are desperate to hide their association with the victim. DS Jack Mackinnon is is leading the case but the closer he gets to the truth the more he feels his own family could be at risk.

Cleverly written plot and the characters are starting to leave their mark on me making this a very good police procedural thriller. I feel a lot more confident approaching the third book after reading this than I did after book 1.
Profile Image for Lynxie.
711 reviews78 followers
December 24, 2012
Deadly motive is a fast-paced and twisting crime thriller. The Mystery is thoroughly thought out and is not obvious. This takes a brilliant writer to produce this level of suspense without letting the cat out of the bag in advance.

I liked the characters, DS Mackinnon (Jack) and DC Brown (Charlotte) were realistic and believable. They had their flaws and they worked with them, instead of being Hollywood-ised. This was a nice change. The down side to this was that I wanted to know more about their personal lives. You were provided with some aspects of their lives outside of work, but I felt it was too restricted. I wanted to know more. I did, however, love the involvement of Charlotte's Nan, that is a soft spot for me at the moment and it made my connection to Charlotte that much stronger.

There were some unanswered questions in this book, but not to do with the main plot, more to do with the personal aspects we were introduced to. This annoyed me more than anything else, because I wanted to know how things worked out for them.

Now, I understand that some of these questions I have may be answered in the recently released Deadly Obsession, but I haven't read that, even though in chronological order I should have. Oh well... That will be the next of Butler's books I read for sure!

The science aspect of the story was well researched and was interesting. It felt relevant to the story, without going overboard and into too much nerd-speak. This also, is hard to do, and I think Butler did it well.

If you're looking for a punchy crime book to read, give Deadly Motive a try, you might be surprised how much you enjoy it!

*Note: I received a copy of this book in return for an honest review*
Profile Image for Jenn.
1,647 reviews33 followers
June 24, 2012
I have to admit, I was a little afraid of the science aspect of this police procedural when I first began reading. Science and I were never friends when I was at school. Science used to try and beat me up along with math. It was just myself and art and English, both very wimpy, and we usually had a good walloping from just the two of them! I'm glad to see though, that my fear was unfounded. There was just enough smarty pants on science that I wasn't put off and very much enjoyed what I read.

At times, I found it difficult t keep track of the characters, however, by the end of the novel I had them all straightened out. And often wondered why I was confused in the beginning as they all were unique and quite easily distinguishable. I can easily see the Stuart MacBride influence in D's writing style. It's a great influence and I know we both enjoy his writing very much. I.m looking forward to reading the next installment and watching the DI and D'S grow. I think they'll be very good for each other and hopefully will not fall into each other's arms as love interests. Bestest buddies would be great. Arguments galore would also work for me. But, please, no smoochies and waking up next to each other in bed (unless it was a horrible, horrible drunken mistake! LOL)
Profile Image for Vishal Bagaria.
Author 6 books13 followers
October 10, 2019
Extremely disjointed and no work on character development. Especially with regard to the past that Mackinnon and Charlotte had shared, or the parallel story of Ted and Wolf - just left hanging in there, without the circle closing. The criminal’s motivations to execute the ancillary crimes were also forgotten. DCI Brookbank’s sudden change in attitude towards Mackinnon halfway through also not explored at all. The strategy of letting the character build chapter-wise and reaction-wise was a bold but a fizzled out move. Enjoyable but not satisfying eventually.
Profile Image for Emma Taylor.
157 reviews3 followers
August 10, 2024
Another good story by D S Butler and a read that flowed so well! I love the writing style and loved that it was as a slightly different storyline to what I’ve previously read with animal rights. Roll on number 3!
Profile Image for Kirsten Schlewitz.
409 reviews30 followers
August 7, 2019
I said after Book 1 (which apparently was actually written later in the series, but takes place before) that I'd give the author a chance to develop the series more. I still think she'll get there. I don't quite understand MacKinnon's personal decisions—for example, he's moved in with his girlfriend, despite not seeming to like her that much—but I do like Charlotte, his partner, and hope she sticks around and we learn more about her.

As for the plot, well, it seemed to take a while to really get off the ground. While I'm sure the science was well-researched, everyone involved with the laboratory suspected to be involved in the poisoning is not only suspicious, but almost inerringly obnoxious. I feel this plot had definite potential, but the number of suspects muddied the waters in a way that didn't advance the story, and made it less enjoyable.
Profile Image for Sharon.
191 reviews6 followers
July 20, 2012
Very cleverly written plot with no obvious hint of who's behind the crimes, it draws you into the suspense as the tension builds at a steady pace. Good introduction to the main characters, with just a little background history of their lives, which cleverly leaves you wanting more. Excellent description & details which not only makes it a great read but had me thinking many times throughout reading this book that it would make a good tv series. I'm looking forward to the next DS Mackinnon & hoping Charlotte will also make an appearance in it. Throughly enjoyable read with great suspense from beginning to end.
Profile Image for Alexis.
2 reviews
May 4, 2012
Another new detective in the writing world- -Jack McKinnon... Liked the way science ran through the the story which shows the author's background. Looking forward to the sequel with the will they won't they Charlotte/Jack thing. Maybe needs more about their backgrounds and personal lives...but really enjoyed it!
Profile Image for Lorraine.
42 reviews1 follower
July 30, 2019
good read bit jumpy at times but enjoyable.
Profile Image for Carôle Ceres.
892 reviews9 followers
May 16, 2024
I listened to the audiobook version of this title. I read this title first (out of order), because it’s currently part of the free Audible Plus Catalogue, but will be expiring on that platform soon (as will book 3).

I’m still feeling my way with the main characters (I don’t know who will be recurring or not), so I will reserve judgement. As for the storyline… this was intricate and intriguing. The characters were all credible (and suitably interesting or irritating as suited their personalities).

The narrator, Rupert Bush, is very good; calm and not overly dramatic. I think that this is a series I can follow and enjoy. On to book 3, whilst it’s still in the Plus Catalogue.
Profile Image for M R B Davis.
707 reviews5 followers
May 22, 2021
A confusing story

The first half of this book was strange. Not much regarding McKinnon or his new found relationship. The story hopped from one to another of the characters. And it got a bit confusing. A bit of a twist towards the end but the protagonist was flagged, in my view. I felt this might be the last of the series i might read. But maybe another to see if things improve?
53 reviews
August 24, 2021
Not a subject I want to read

I love reading and i love thrillers and very recently I have found the crime series books and greedily devoured all of Caroline Mitchell's Amy Winter, Ruby Preston and Jennifer Knight loved every one.
So to carry on AS Butler had good reviews and I enjoyed Book 1 DS Jack MacKinnon but this book 2 has left me cold and I have given up before I reached half way as I read for enjoyment and I wasn't enjoying the subject.

Profile Image for Mr Mark Hawksford.
353 reviews6 followers
May 20, 2024
Deadly Motive -

This is the second book in the series. I am not 100% sure about how to review this book. Whilst I enjoyed the book, I did feel that the plot was a little weak and similar to the first book, the conclusion was wrapped up quite quickly. There were also parts of the book around their personal life’s that didn’t really seem to go anywhere. I was a little disappointed in the end. A 3.75 out of 5 from me.
Profile Image for Teresa Perrott.
151 reviews1 follower
May 22, 2020
Brilliant

When a supporter of Oxford University science labs is found murdered, everything seems to point to the animal rights protests but is it that simple? Through in Jack having moved in with his partner and her two daughter was well and you have a book full of twists and turns .
Profile Image for Michelle.
777 reviews9 followers
June 1, 2021
3.5/5
The mystery is really 4/5, but the main characters are all over the map and that knocks my rating down. Warning: Animal experiments are discussed briefly and at the heart of the story.

I doubt I will continue with this series, even though I like the author and her previous serious with a female lead Detective. I just could not find a connection with these characters. Basically, I did not like any of them!

The mystery, however, was well paced and kept me guessing
Profile Image for Mrs Susan Lindman.
4 reviews
December 8, 2018
Deadly Motive

Good read and slightly different to what I expected, well thought out and twists and turns kept coming up where you tried to guess if that person did it to find a totally different person did. Bit of an open ending but enjoyed the book.
Profile Image for Nathan Hill.
130 reviews4 followers
March 8, 2019
Another great read

I am getting to know the characters normal flawed people who are brought to life within the pages..The plotting is good and I didn't guess the ending.just downloaded the next book in this serp
517 reviews3 followers
June 7, 2019
Maybe one to many chapters

Cannot fault the descriptive quality of the writing, however this did take away from the storytelling somewhat. It felt like there were great rafts of describing weather, clothing etc., Good story needed to be 60 chapters shorter.
Profile Image for Jackie Bradman.
246 reviews
March 12, 2020
This is a real grower... starts slow & somehow worms it’s way into your mind so it’s all you’re thinking about. Unfortunately, the who & why was revealed at breakneck pace leaving me bewildered & feeling cheated
668 reviews6 followers
May 14, 2020
Another beautifully written episode in this Author's catalogue,

of good tales. I ike the subject mattet and
attention to detail in the procedures. Very much appreciated amd enjoyed.
34 reviews
July 11, 2020
Thrilling

Second book featuring DS Jack MacKinnon great read good to see Jack got the bad guy again looking forward to the next one. Would highly recommend reading this to those that like this kind of book.
Profile Image for MR DANIEL BISHOP.
1 review
August 2, 2020
Not my favourite DS Butler book so far. This one took a while to get going, I hung in there though. It felt like too many topics were included and there wasn’t enough time for the author to cover each of them. I will continue with this series and hope book 3 has a bit more going for it.
Profile Image for Annie.
223 reviews6 followers
June 11, 2021
Couldn’t really connect to the characters. Can’t quite put my finger on what it is. The story I dunno, seems boring and slow. I found the same with the first book but thought give 2nd book ago in case it was my mood.
7 reviews
May 31, 2022
difficult read

I feel there should be a warning at the beginning of this book regarding the descriptions of animal cruelty and using animals within laboratories. I ended up skipping much of the book as found it too difficult to read

Profile Image for Kirsty.
48 reviews1 follower
February 23, 2023
I really struggled to get into this book. It was way too busy and slow. But finally the last couple of chapters it came into its own. I persevered because I want to read the series. I hope the next isn’t like this one or else I won’t continue.
1 review
July 25, 2023
Having worked in a science facility I found some of the science very unrealistic but apart from that good storyline, interesting & unexpected end. Bit bored with some family issues which are ongoing but great book.
Profile Image for Dobby.
563 reviews35 followers
April 20, 2025
TW: Animal abuse theme/brief dog fighting scene

This was a tough one for me to read. I almost DNF'd. I will continue with the series, since I'm just finishing the second book. However, I do prefer the Detective Karen Hart series, which I read first.
1,181 reviews6 followers
October 15, 2025
Good Story

Another good story from D S Butler. I have read all her books but I found it difficult to get involved with the storyline in this one. I will still be reading any future books however.
Profile Image for sandra.
141 reviews1 follower
August 22, 2017
Kept me guessing

I enjoyed reading this book it kept me guessing who the culprit was and I was wrong every time lol
Displaying 1 - 30 of 61 reviews

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