Who doesn’t love a good murder?

Crime fiction is one of the world’s most popular genres, equating for 10% of paperback sales in the UK in 2015, and 28% of ebook sales.

And from Making a Murderer, to Real Detectives (my favourite), to podcasts like Serial and Untold: The Daniel Morgan Story, we can’t get enough of true crime either.

The mystery, the intrigue, the fact that these stories could happen to someone we know but are distant enough that we don’t actually believe it will happen to us, all help to draw us in.

However, when it comes to writing crime, there are significant differences between writing true crime and writing crime fiction.

Let’s take a deeper look…

Crime fiction has to tie things up, true crime doesn’t always have a resolution

There are many famous true crime stories where, decades or even centuries later, the killer still hasn’t been caught. Jack the Ripper, The Black Dahlia, and The Zodiac Killer are just a few of the more famous examples.

The unsolved element is what makes these murders so fascinating—many of us get wrapped up, hoping to play detective ourselves. That’s why many of us read crime.

But we read true crime with different expectations to fictionalised crime.

Our expectations of true crime are different to our expectations of crime fiction.

If the murderer in your crime fiction isn’t caught, readers will be left unsatisfied. They can’t play detective because they only have the information you gave them. They can’t dig any deeper to solve the mystery.

With true crime, this isn’t the case—there’s always somewhere else the reader can look to find more information on a case, whether that’s a book, a documentary, a key witness, or of course, the internet.

Crime fiction has to be believable, true crime doesn’t

There are plenty of true crime stories that, if you didn’t know they were real, you wouldn’t believe. This is the biggest distinction between all fiction and nonfiction: fictional stories must be believable…even though much of what happens in real life—and makes the news—is often inconceivable.

No matter how convoluted your plot is, your reader must be able to get their head around the reason(s) why your murderer did what they did. In real life, some people just want to see the world burn. This is a much more difficult reason to pull off in fiction, and there’s a high chance it will divide readers—some will be satisfied, others won’t.

Gone Girl, while more of a thriller than crime fiction, is a good example of this. (Spoilers ahead.)

No matter how ridiculous Amy’s behaviour, we must believe why she behaves the way that she does. We must believe she thinks what she’s doing is right, even if we know it isn’t. We must also believe that despite everything that happens in the novel, neither she nor her husband Nick will ever change, because they’re both just as bad as each other.

Personally I loved the ending and thought it was genius, but I do know some people were left unsatisfied because they stayed together and nothing changed. If you write an ending such as this, be prepared to divide your readers.

Crime fiction has to have characters the reader can empathise with, true crime doesn’t

Like all great writing, you need to create characters your readers can empathise with. Doing so is one of the best ways to keep them reading through to the end.

In real life, even the good people among us can do heinous things.

Even if you’re writing the stereotypical drunken detective, they still need their save the cat moment for us to a) like them and b) understand why they care enough to investigate a crime.

When it comes to true crime, you can’t control who committed an act. You also can’t control how likeable—or unlikeable—the lead detective is.

Crime fiction has to be formulaic, true crime can take any path

Readers of crime fiction have expectations. And from red herrings to the murderer’s motives, you must fulfil them.

If you don’t follow at least some of these conventions, you may find agents/publishers steer you towards either changing your narrative to include those tropes, or changing your book to fit into a different genre. Genres are all about marketing, but loyal readers stick to them for a reason.

Readers of true crime don’t know what path they’re going to be taken on unless they’re already familiar with the real-life events covered. Some people love this about true crime, some people are left deeply frustrated by this…

Villains in crime fiction need a reason for their actions, real-life villains don’t

Why someone commits a crime is a crucial part of crime fiction.

In reality, some people are just evil.

There are plenty of cases of people—even children—with middle-class, apple-pie upbringings that commit heinous acts. That doesn’t fly in crime fiction. Someone with a good life being pure evil is just too inconceivable (and terrifying) to get our heads around.

When writing crime fiction, you start at the resolution and work backwards

To write crime well, you MUST know who the killer is before you begin. Crime fiction needs plotting more than any other genre. Failing to plot results in all sorts of plot holes and poor red herrings. J.K.Rowling plans every red herring and every plot point in her stories, and doing so has clearly paid off.

I’m not saying you can’t write a book without plotting first, but pantsing makes more work for yourself and means you’re far more likely to get stuck.

The last time I wrote a crime story without knowing who the murderer was, they changed three times. I ended up hating the project so much that I almost stopped writing fiction all together. Save yourself the frustration—plotting doesn’t take the creativity out of writing, it stops you from digging yourself into a hole.

Crime fiction needs to centre on a handful of characters; in real-life, it takes a small village to solve a crime

Having too many characters in your crime fiction makes it difficult for readers to follow. That’s why you’ll often find MEs doing forensic tests even though they’re a totally different skill set and in reality would fall to a completely different department.

Try to keep your team small if you’re writing fiction. Focus on the most important ones and have the other characters as secondary, tertiary, or flat characters.

Real police methods aren’t as neat and tidy as they are in the books

Books make every journey seem neat and tidy, but they never are.

Investigations don’t follow linear paths and it can take months, even years, to solve crimes. Even if a detective is certain of who’s responsible, if they don’t have any concrete (often physical) evidence, they won’t get a conviction.

Detectives may also work on several cases at once, increasing their workload and further increasing how long it will take to solve the crime.


While true crime can inspire crime fiction—and even vice versa—writing the two is very different.

True crime reflects how unpredictable real life can be, while crime fiction is as formulaic as you can get. That doesn’t mean you can’t play with the genre, but it’s always important to understand the rules before you break them.

What are the differences between true crime and crime fiction, and what does it mean for your writing?

Thanks to Silvia for the post idea!

Do you prefer true crime or crime fiction?

What is it you love about (reading or writing) crime? Let me know in the comments!