The Poisonous Solicitor: The True Story of a 1920s Murder Mystery (2022) by Stephen Bates

This is the first of what will hopefully be two non-fiction reviews for the blog this week. I am not the biggest true crime fan, but this one caught my attention as it was a case which inspired several interwar mystery novels, and it gets direct mentions in others.

Hardback cover for The Poisonous Solicitor. It is a red design with a photograph of Major Armstrong (with the background removed). There is a double black line border.


‘On a bleak Tuesday morning in February 1921, 48-year-old Katharine Armstrong died in her bedroom on the first floor of an imposing Edwardian villa overlooking the rolling hills of the isolated borderlands between Wales and England. Within fifteen months of such a sad domestic tragedy, her husband, Herbert Rowse Armstrong, would be arrested, tried and hanged for poisoning her with arsenic, the only solicitor ever to be executed in England. Armstrong’s story was retold again and again, decade after decade, in a thousand newspaper articles across the world, and may have also inspired the new breed of popular detective writers seeking to create a cunning criminal at the centre of their thrillers. With all the ingredients of a classic murder mystery, the case is a near-perfect whodunnit. But who, in fact, did it? Was Armstrong really a murderer? One hundred years after the execution, Agatha-Award shortlisted Stephen Bates examines and retells the story of the case, evoking the period and atmosphere of the early 1920s, and questioning the fatal judgement.’

Overall Thoughts

I can be guilty of skipping over forewords sometimes, but I am glad I did not do so in this case, as not only was it useful to know of the two other major retellings of the case (both of which take opposing views on whether Major Armstrong was guilty), but I would have missed out on the unusual information that one of these previous authors (also a solicitor, like the major), ‘not only found himself working in the same office as the major, even occupying his desk and chair, but who also later moved into Armstrong’s former home.’ Talk about commitment to a project!

The opening chapter briefly recreates the scene of Katharine Armstrong’s death, highlighting some details which did not make it into the trial. One of the things which comes out strongly in this first chapter is Herbert Rowse Armstrong’s high levels of respectability, something which made this case all the more shocking and attention grabbing at the time. We are reminded that his was ‘the only solicitor ever to be executed in England, certainly in modern times.’ George Orwell’s ‘Decline of the English Murder’ (1946), is also brought into the wider discussion on how the case was reacted to and the cultural legacy it left. Orwell poses this question:

‘What would be, from a News of the World reader’s point of the view, the “perfect” murder? The murderer should be a little man of the professional class – a dentist or a solicitor, say – living an intensely respectable life somewhere in the suburbs and preferably in a semi-detached house… He should be either chairman of the local Conservative Party branch, or a leading Nonconformist and strong Temperance advocate … Having decided on murder, he should plan it all with the utmost cunning, and only slip up over some tiny unforeseeable detail. The means chosen should, of course, be poison … a crime can have dramatic and even tragic qualities which make it memorable and excite pity for both victim and murder.’

Even those with a superficial knowledge of the Armstrong case will see the many parallels to the hypothetical one Orwell describes as being satisfying to read about. Bates suggests the parallels are so significant that Orwell must have had the Armstrong case in mind. Finally, the opening chapter also provides information on the geography of the area lived in, pointing out its literal and social isolation, as well as the way it was culturally and technologically out of kilter with the “Roaring 20’s”. I think the information was not overdone and Bates does tie it back into the case.

Following on from this, the book then considers the events running up to the death of Katharine Armstrong. One factor I was particularly interested in was an earlier poisoning case in the Kidwelly area, in 1919. Mabel Greenwood died of poisoning, and her solicitor husband was arrested for the crime, but ultimately, he was acquitted due to the sloppy nature of the prosecution’s case. This did not go down well locally nor nationally and Bates argues it impacted how people reacted to the Armstrong case 18 months later. He suggests it created a determination in certain individuals to make sure that another solicitor did not get away with murder.

Unsurprisingly we also get the background on how Herbert and Katharine met, as well as information on the progression of Armstrong’s career. This latter aspect was adversely affected by the impact the end of WW1 had on the rural and agricultural economy, including the price of grain and land. You might be thinking this sounds like a tangent, but Bates is able to clearly show how this factor built the foundations for a motive mentioned at Armstrong’s trial in regards to the attempted poisoning of a rival solicitor, Oswald Martin. Before reading this book, I was not aware of this additional poisoning, yet it was Martin’s illness (or poisoning depending on how you read the evidence), after taking tea with Major Armstrong, combined with some poisoned chocolates sent to his in-laws, which led to the police even looking into the death of Katharine.

Aside from issues at work, the physical and mental health of Katharine is also explored, as she had only been released four weeks prior to her death, from an asylum. Extreme depression and her reduced ability to function physically were the symptoms which led to this stay, the cause given was going through the menopause. The menopause was often described euphemistically and it is not something which is often explicitly mentioned in crime fiction (the genre I am more familiar with) of the time period. The Straw Man (1951) by Doris Miles Disney is the only one I have noted as doing so.

I felt these early chapters helped the central participants in the case come alive and knowing these background details really helped my understanding of the defence and prosecution’s cases once Major Armstrong was brought to trial. One thing I appreciated about Bates’ approach to the project is that when it comes to more gossipy evidence or insinuations, he uses original sources to question how accurate they are. An example of this is how those for or against the major interpreted his holiday after his wife’s death. Bates also looks at the other possibilities surrounding Martin’s illness and considers the impact his in-laws had on there being a growing suspicion towards the major in the first place.

Legal procedure is not at the top of my list of interesting things to read about, but I enjoyed learning about the initial hearing for the Armstrong case and even at this early stage, there were multiple instances where there was a lack of professionalism. The major is neither canonised nor demonised in Bates’ book, but there is humaneness in his depiction. We are allowed to see and even feel those moments of shock the major must have experienced. For example:

‘The initial court hearing on 2nd January had lasted for just fifteen minutes, The committal proceedings in the tiny courtroom starting the following Monday, 9th January, would drag on over ten days for the next six weeks. To start with, Major Armstrong would have thought that the case against him dealt merely with the alleged poisoning of Oswald Martin. It was only on the fifth day, at the start of the second week – nearly three weeks after Armstrong’s arrest – that he learnt that, much, much worse, he was also being charged with murdering his wife; a crime for which if found guilty he could be hanged.’

I think it was at this stage in the book and this stage of the investigation that I felt Bates’ book encourages you to be an armchair sleuth, evaluating the evidence brought forward. Another element of the reading experience I also thought about was the effect of knowing the outcome of the trial before reading about it. Does it almost create a fatalist or tragedian effect?

For his trial, Major Armstrong had Sir Henry Curtis-Bennett defending him and I was interested to learn that later that year he would go on to defend Edith Thompson. I felt Bates tells you the right amount of information about the key players in the case and I found myself engaged in learning about Sir Henry’s approach to defending the major. In particular I was intrigued by the information that he chose to leave out, such as the testimony from the eldest daughter concerning the time her mother claimed to have taken an overdose of medicine. The daughter was discouraged by the local vicar, amongst others from sharing the information, which is interesting given how it would have helped the defence’s argument that Katharine took the poison herself.

Bates’ book also illustrates how a crucial factor in ensuring the conviction of the major was the judge presiding over his trial. Again, we are shown the importance of knowing an individual’s background, using it as a lens for understanding why they behaved the way they did. Bates shows plenty of evidence for how the judge was biased towards the prosecution from the get-go and often intervened to help their cause, either taking over the questioning of a witness or forcing the defence medical experts at times to only answer questions with ‘yes’ or ‘no’. In the summing up the judge even added new hypothetical information about how the poison was administered that neither the defence nor the prosecution mentioned. It is fair to say that a different judge may have made a big difference for the major. There are many flaws in the prosecution’s case which Bates examines and suffice to say I think based on the evidence of the time; a modern-day court would not convict. However, that is not the same as saying that the major was not guilty.

Another nail in Armstrong’s coffin was his own defence team. Some things were arguably not their fault, such as key witnesses changing their testimonies between the initial hearing and the trial (something the judge does not pull them up on) but other actions they took certainly backfired for the major and damaged his case. A fact which stayed with me from this part of the book was that when the major took to the stand, he was asked over 2000 questions across two days without any seat to sit on, which reminds you how gruelling an ordeal standing trial was.  

I very much enjoyed looking at the photos in the middle of the book. I thought they were more interesting because I had read about the people first that are they shown in them. This left me wondering are you a reader who waits until you arrive at the photos section of a nonfiction book too look at them, or do you look at the photos before you start reading?

Bates brings out a lot of interesting details about the aftermath of Major Armstrong’s trial, including the bitter twist of irony that Mabel Greenwood’s husband wrote an article (probably ghost written) commiserating with Armstrong and his fate. Talk about rubbing it in… One of the jury members also discussed the case with the newspapers afterwards (before it was illegal to do so) and this also provided a fascinating insight into how Armstrong was perceived. The fate of the major’s three children is also looked at and Bates is sensitive in considering the impact this would have had on them.

There is a small section in the book which explores how the case fed into the writing and consumption of detective fiction of the era. This was a little generalised in places, but it was interesting seeing which mysteries were inspired by the case or directly mention it, such as Anthony Berkeley’s The Poisoned Chocolates Case (1929) and Malice Aforethought (1931), as well as Dorothy L. Sayers’ Unnatural Death (1927), Strong Poison (1930) and Georgette Heyer’s Detection Unlimited (1953). This is a topic I would have liked to have read more about, but it did get me thinking about what other examples there are. If you know of any do share them in the comments section below. I wondered if Joan Coggin’s Dancing with Death (1947) shares a parallel with the case in that the act of buying weedkiller in January is regarded as suspicious in this story. In the Armstrong case, the major’s decision to buy arsenic in winter to make his own weedkiller is similarly seen as implausible and dubious. There is also a poisoning mystery by Sydney Fowler called Rex v Anne Bickerton (1930). Martin Edwards writes about this book on his blog saying that: ‘The main point of the book, it seems to me, is for Fowler to turn his fire on the legal establishment. The police come in for a kicking, as does the judge and the prosecution.’ This attack on the ‘legal establishment’ made me wonder if it was influenced by the Armstrong case, given the unfair trial the major seems to have received.

Bates has an engaging writing style and unlike some true crime fiction his prose is not stodgy. I think there is a bit of repetition with some pieces of information, but this issue is not too extensive across the whole piece. The book sets out the information for the case, engaging with contemporary sources meaningfully. Throughout the book you don’t find the author giving a personal slant or opinion on the evidence. It feels like the reader is being given the space to make their own minds up as to whether the major was guilty or not. Nevertheless, when it comes to the writer’s summing up, I would have liked to have seen their view more clearly demonstrated. It is hard to tell what their opinion is on the case. Reading between the lines, and I could be hopelessly wrong, but I think the idea I took away from the summing up was that although the Major Armstrong’s trial was unfair and downright shoddy in places, the major probably still did the crime.

One thing which suggested this to me was that in the summing up, Bates includes a further poisoning incident which was not mentioned at trial. The victim this time survived, and was a tax professional who dined with the major and had one of his cigarettes. The victim had a horrific night and seemed to have survived his poisoning experience through copious tea drinking and throwing up. The following morning a medical acquaintance said his breath stank of arsenic and the police later contacted him saying the cigarettes he smoked from were shown to contain that particular poison. This piece of information, to me, seems to have been held back from being mentioned earlier in the book. This arguably makes for a surprise twist, just when the summing up seems to be suggesting maybe the major was innocent after all. Consequently, I wondered therefore if the placing of the incident was significant.

As said previously I do not read a lot of true crime, but I would read more by this author on similar cases from the early 20th century. I think fans of crime fiction from the 1920s and 1930s would enjoy this book, not least for its armchair detecting possibilities.

Rating: 4.25/5


  1. Interesting. My memories of the case are that a packet of arsenic was actually found on him when he was arrested for trying to poison a rival attorney, and that the subsequent exhumation of his wife showed extensive arsenic poisoning.

    Liked by 1 person

    • Yes a packet came out of his pockets, stuck between some letters. He said at the time that he had divided the arsenic into 20 packets and thought he had used them all. The jacket he was wearing was his gardening one and he had been planning to do some gardening when he went home from the office. And you are correct again about the wife – 3-4g of arsenic found.


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