Murder in the past: building a plausible mystery before forensics

Murder. It holds a timeless fascination that few other crimes can match. It’s hard to get excited about a character wearing excessively pointy shoes or selling underweight loaves – but when a corpse turns up, people pay attention.

Modern forensic techniques are, well, modern. As is the idea of a structured police force. The Bow Street Runners didn’t come along until the mid-18th century. When there are no clear police procedures to fall back on, or someone whose job it is to sort things out, writing a murder mystery can feel daunting. A modern murder mystery author can draw upon published works on forensics, ballistics, chemical testing, and all the other resources a ‘proper’ police investigator can draw upon to catch the baddie. Writing one set in the past presents a special challenge.

Without the crutch of a modern setting, the historical writer must turn to the core of the genre. Logic, motive, and deduction – a historical setting lets you get back to the bare bones of a murder mystery, and write a truly thrilling story.

Know your limits

This is going to require some research. You need to understand what exactly your protagonist will know in terms of medical and scientific matters. A Tudor sleuth will no doubt be aware of some poisons and how they can affect the body, but they will have other constraints. For example, no DNA testing. Blood is, well, blood. There is no way to tell if it came from the victim or somewhere else.

These realistic constraints help to draw the reader into the story and keep your setting authentic. There is room for a little flexibility. Perhaps your Tudor sleuth has travelled extensively and picked up medical knowledge from different traditions – say, learning to recognise the signs of an opium overdose while working alongside apothecaries in a major trading port. But be careful with this; no one wants to read about a smug know-it-all.

Understand the basics

Means – how they did it

This is in many ways the hardest one to do. Do some research on historical poisoning techniques, or otherwise ensure that the victim meets their maker in a logical and interesting fashion. It needs to be complex enough to make a mystery, but not convoluted enough to rely on outrageous coincidence and luck. This doesn’t need to be an obscure plant or rare toxin. It can just be a good old chair leg to the back of the head. Mind you, there is something very satisfying about bumping off your victim with a period weapon. Let your Saxon sleuth find a bloody seax hidden in the bushes, rather than just a generic knife.

Your oldie-timey assassin also doesn’t have to worry about fingerprints, DNA testing, ballistics, CCTV, or mobile phones. So they can slay to their heart’s content knowing they won’t accidentally leave behind an invisible piece of themselves at the crime scene or be recorded. But what period-appropriate clues might they leave behind?

Motive – why they did it

Universal motivations like greed, jealousy, or lust will resonate with a modern audience, but it’s also worth exploring other, setting-specific motives. History is full of strange cults and esoteric beliefs, so if you need an occult motive for your murders, you’re spoilt for choice. The concept of ‘honour’ varies dramatically from period to period, but for the right person, it can definitely be worth killing for. Under this category, I’d also put status in high society, or a position at court, and the power these can confer. People have killed for far less.

Opportunity – circumstances conspire

Opportunity is the specific set of things that allows the killer to strike. It can be either premeditated (for example, waiting until the festival of Lupercalia when the victim would be running through the streets), or opportunistic (the Duke of Buckingham creates a scene at dinner which distracts everyone enough for the killer to slip away unnoticed).

Let your setting help you out here. I used Lupercalia as an example, but other religious festivals, or seasonal events and celebrations, give your killer plenty of convenient places to strike.

Can I get a witness?

Let’s talk about witnesses and testimony.

Without CCTV, if you want to find out what happened, you need to talk to people.

First off, period-specific experts. At some point in your sleuth’s investigation they might need to call upon professional help. In modern times, this is the forensics department and the CSI team. But in the past, there were other people your sleuth could reach out to. Weird powder under the corpse’s fingernails? Speak to an alchemist. A scrap of cloth caught on the doorway? A wool merchant can tell you where it’s from. These period expert witnesses not only help to move the investigation along, but they also make your setting feel alive. They give a sense of a wider world that is trundling along outside the book and help to draw the reader in.

Character witnesses are important too. Even if the victim was famous or known to your sleuth, having other people to ask “did he have any enemies?” and direct their social enquiries to can be really useful.

Bias is a huge factor as well. For much of history, the word of those from marginalised groups carried little or no legal weight – especially against their social ‘betters’. A challenge to your protagonist could be that despite one of these outsiders being a direct witness, without hard proof the killer will walk away scot-free.

Which reminds me…

Bias and superstition

Class was a major barrier to justice in the past. A noble who gives his solemn word, or swears on holy relics, will almost certainly be believed. And even if his servant saw him doing the murder, they would be very hesitant to speak out against him. Fictional investigators will need to tread carefully when navigating social hierarchies.

Gender bias was equally pervasive. Women were discouraged from asking too many questions, let alone solving crimes. That’s not to say no woman ever railed against those boundaries, but she would’ve come up against scepticism and resistance if she tried.

These biases make great obstacles for your sleuth. Let’s say you’re writing about a novice nun investigating some horrific killings. She will have to deal with not only medieval attitudes towards women, but also the rigid hierarchy of her order.

Another limit of the setting might be superstition. For most of history, a sincere belief in magic, the occult, and supernatural creatures was the norm. Eventually (unless you’re writing some historical fantasy), these will give way to a rational explanation. Having your protagonist investigate an apparent death by witchcraft, only to dramatically reveal the real method, can be very satisfying.

Ok, so what can I use?

We’ve spoken a lot about limitations; let’s talk about what your sleuth has at their disposal. Witness testimony we’ve covered, but some universal skills and clues can help you catch the killer.

Physical clues must be visible to the naked eye. Fingerprints aren’t a thing yet. But you can still drop clues like mud, fragments of clothing, injuries and marks on the body, or even the murder weapon. They are the easiest type of red herring to slip in as well. But one word of warning about red herrings – don’t use too many, or it starts to seem fishy.

Pattern recognition is useful, especially if your killer is stacking up multiple bodies. You should link this to your setting and the wider events going on around the sleuth. Again, this helps to tie your story into the world and draw the reader in.

Good ‘ol logic is always a winner. The process of elimination, deduction, critical thinking – these processes are freely available and will be familiar with any murder mystery reader.

Social inquiry (talking to people) is going to vary a lot by period. Simply put, in Victorian times, you waited to be introduced. You couldn’t just rock up at someone’s house and say hello, that would be frightfully rude. Also, people stick to their social classes. Finding interesting ways for your sleuth to navigate social pitfalls in their enquiries can be very entertaining, both to write and read.

Throw away the crutch

Writing a historical murder mystery has its challenges, absolutely. But when you take away the safety blanket of modern science and police procedure, you have the opportunity to craft a really special story. One that moves beyond just a puzzle to be solved.

The focus shifts from test tubes and lab results to people. People, their motives, and their psychology. Frankly, in my humble opinion, being able to bring the past to life like that is the holy grail of historical fiction.