Solving Crimes of Murder with DNA

Today’s forensic science makes crime-solving look easy. According to movies and television shows, all you need to do is swab something icky, do something science-y, and something changes colour. A mystery gets solved. A perpetrator goes to jail.

There are flaws in simplifying DNA science through on-screen fiction.

Sure, a narrative moves a lot faster without the unnecessary technical specifics that go along with it, but when huge holes are created, it leads to misconceptions about the process.

The top four misconceptions about DNA science made by audiences are:

• It’s an easy science
• It’s fast
• It’s available anywhere, all the time
• It’s been around forever

Firstly, the process is still relatively new. It’s so recent (and expensive) that not every country has access to it.

Not every major city that has a science lab can run these types of tests. Those certified to test don’t turn DNA tests around quickly. TV shows have faux scientists flipping faux tests in under an hour. The reality is that it takes weeks to months to get results.

There are a few more important elements to consider about DNA science.

How the DNA is collected.

Where it’s collected.

The handling of DNA after the collection takes place. (How many hands does the DNA pass through to get to an approved testing facility? It’s as intricate as the science itself)

If any step in the evidence chain is incorrect, the results are questioned. Any error in the science leads to wrongful acquittals or convictions.

Sure, sensitive machines do the microscopic heavy lifting, but samples can become contaminated by other DNA before the tests even begin, thereby rendering their outcomes inadmissible.

A blood sample taken from a kitchen floor is already contaminated by cells present before, during and after the blood was deposited there.

It contains the cells of those who have used the kitchen. People have coughed and sneezed in it. Pets have walked over it, and bacteria live on every surface before and after every clean.

The longer the blood was exposed before collection, the more likely other cells were to be included in the sample’s mix. Even the swab itself can be a source of contamination if not handled properly.

Discriminating one cell from another requires skill. It’s finding an invisible needle in an invisible needle-stack.

Everyone and everything in the chain must do their job properly to ensure a successful, accurate, and usable outcome that sticks in Court.

None of it happens easily or quickly.

Once upon a time, it didn’t happen at all.

Before this, we relied on fingerprints and witnesses to secure convictions. The evidence used had to be seen by the naked eye to be believed by juries.

And then came that wonderful moment in history when DNA science was introduced into a law court for the very first time. It was experimental. It made huge claims. It had no historical data to support them. Lawyers fought for and against using it.

When the science eventually proved its reliability, it marked the beginning of a change in the law and in the way police investigations were conducted. With the right tools, previously invisible evidence suddenly became visible.

But there was a magical grey area between having no DNA science and then accepting it as standard practise.

I say magical because this is where some of my writing goes.

I look at a crime committed at the threshold of DNA science — from a time when no one used it — to another time when it’s expected. A new piece of evidence arises.

It’s then it’s weaponised.

A modern researcher comes across it. It was found on the surface of a love letter and threatens to reveal a long-hidden truth.

This transitional period intrigues me. It makes me wonder how many real-life criminals live in fear of being caught because of new DNA science. All it’d take would be a piece of new evidence to surface. Police could catch up with them decades later and arrest them.

SEETHINGS follows this idea. Part of the narrative follows a seemingly ordinary individual who is about to have their world turned upside down.

Someone found evidence of an affair. There is DNA on a decades-old document. If the DNA on that letter holds up, it’ll lead to a more diabolical crime. Our personable, much-loved individual will suddenly turn pale. Their colour change is all we need to know.

This villain could be your neighbour or the person sitting opposite you in a coffee shop. They are charming, helpful and kind. There’s no way to know whether my type of villain is already embedded somewhere in your life.

You think your gut knows.

Now here’s an added twist: What if your DNA profile was matched to that of an unsolved murder case from three decades ago? The police knocked on your door and want to take you into custody for an interview.

You didn’t do anything to anyone. You don’t mix with criminals and never have.

You’ve lived a good and wholesome life.

You’re a respected professional, pay your taxes and go to Church each week.

Nothing in your life has led you to commit a crime. Never. There’s no criminal history. There never will be.

You’d deny committing it. Of course, you would. That’s logical. There’s no need to explain yourself to anyone. You simply didn’t do it. You’re incapable of it.

There must be an error.

Like my protagonist, you’re a decent, kind person.

It’s impossible to be linked to any crime, much less murder. You’re innocent and most definitely know it.

Or maybe you did and just don’t remember how when or why you did it.

-Michael Forman