STEM Tuesday– CSI – Forensic Science and Anthropology- Writing Tips & Resources

Trace Evidence of an Author: Point of View, Purpose, and Voice

In many ways, Locard’s Exchange Principle is the bedrock of modern forensic science. According to Locard, when two things come into contact with each other, like a suspect and a crime scene, they transfer materials. This explains why a suspect leaves behind trace evidence like fingerprints, hair, and fibers from their clothes while picking up tell-tale mud on their boots.

When we write, a similar exchange takes place. As authors, we leave fingerprints all over our work, especially in the purpose we choose, the point of view we take, and the voice we pick. Don’t believe me? Grab your tweezers and magnifying glass and let’s analyze the evidence.

Author’s purpose and point of view

The first, and perhaps, obvious way writers leave traces of themselves is through their purpose and point of view. Two authors writing about the same subject may have different purposes. The first may want to persuade you, while the other wants to inform. Even if two authors have the same purpose, their approach to the subject (in other words, their point of view) is as unique as their DNA. This includes what facts they choose to include or leave out and the conclusions they draw from the evidence.

Let’s take a closer look: This month’s book list features two books about the discovery of the Kennewick Man, a 9,000-year-old skeleton found on the banks of the Columbia River in Washington: MYSTERIOUS BONES by Katherine Kirkpatrick (illustrated by Emma Stevenson) and THEIR SKELETONS SPEAK by Sally M. Walker and Douglas W. Owsley. As an exercise, read the jacket flap copy and study the table of contents for each book. What does each tell you about the author’s purpose and point of view? Do the authors cover exactly the same topics or do you see a difference? Do you think their purpose and points of view are the same? If not, how do you think they will differ? Does one point of view more closely match your own?  



Authors also leave traces of themselves in terms of the voice they choose for a piece of writing. Is the voice humorous? Poetic? Energetic? Formal? Informal? The voice should help the author achieve their purpose and communicate their point of view. Try this activity: Compare a paragraph from MORE ONE-HOUR MYSTERIES (Mary Ann Carr) with Carla Mooney’s FORENSICS: UNCOVER THE SCIENCE AND TECHNOLOGY OF CRIME SCENE INVESTIGATION. How would you label the voice of each? What elements of the writing led you to that choice? Hint: Look at things like word choice, punctuation, length of sentences. More informal or humorous voice might rely on shorter sentences, more exclamation points, and more informal language. 

Your Author Fingerprints

Now, look at a piece of your own nonfiction writing. What’s your purpose and point of view? How would you describe your voice? Why? Is your voice a good match for your purpose and point of view? If not, pick another voice and revise your work.

And don’t forget, Locard’s Exchange Principle is a two-way street. Even if a piece of writing doesn’t work out the first time, every time we write we pick up new skills. That means all our writing leaves its imprint on us, helping us develop and grow as writers.


Kirsten W. Larson used to work with rocket scientists at NASA. Now she writes books for curious kids. She’s the author of WOOD, WIRE, WINGS: EMMA LILIAN TODD INVENTS AN AIRPLANE, illustrated by Tracy Subisak (Calkins Creek, February 2020), CECILIA PAYNE: MAKING OF A STAR (SCIENTIST), illustrated by Katherine Roy (Chronicle, Fall 2021), along with 25 other nonfiction books for kids. Find her at or on Twitter/Instagram @KirstenWLarson.


This month, the Out Of Left Field (O.O.L.F.) Files provides links to learn more about forensic science, voice choice, and much more.

  • Learn more about Locard’s Exchange Principle at Science Struck.
  • The Crime Museum is another fun place to explore Locard’s Exchange Principle and related topics.
  • Need some help deciphering voice? Melissa Stewart has one of the best videos around about The Voice Choice in writing. 
  • Looking for some online brain teasers and mysteries for your students? Check out Squigly’s Playhouse.
  • One-Stop English has a fun “murder in the classroom” mystery activity for students.

Interview with Ridley Pearson, Author of Super Sons

Support Independent Bookstores - Visit and check out Ridley Pearson's The Foxglove Mission.Hey Mixed-Up Filers, we’ve got a super interview for you. Ridley Pearson, author of the Lock & Key, Kingdom Keepers, and most recently Super Sons series is sitting down with us today to discuss the latest book in the Super Sons series, The Foxglove Mission.

This is your second book in the Super Sons series. Can you tell us a little bit about the series and about DC’s middle grade graphic novels?

The most interesting character in suspense is, ironically, the villain. The trilogy of Super Sons books works off three “evils.” Book 1: gangs. Book 2: corporate corruption. Book 3: governments. Sometimes these evils are on the page; sometimes implied.

In The Foxglove Mission, our newest character, Candace, is in search of her lineage, her larger family, and her purpose as a human being. She is surrounded by friends who care about her: Ian Wayne and Jon Kent, the Super Sons. She goes off on a dangerous quest. Jon and Ian follow, trying to help her. The boys have their own missions: to find a way to heal Jon’s ailing mother, and to stop a chemical firm from making others sick. It’s high stakes, high action, and teamwork.  

You’ve worked with characters before that, like the Super Sons, have an already established canon, in projects like Lock & Key, Kingdom Keepers, and Never Land. What was it like working on a story with characters that have so much history attached to them? 

It’s a great question, and that was my question to DC when we discussed my writing these graphic novels. Thankfully, my editors said, “Pay no attention to the man behind the curtain” (i.e., the past of these young superheroes). They allowed me to reinvent them, and hopefully they are likeable, strong characters with much to figure out. That’s how I felt as a kid.

Why Damian Wayne and Jon Kent? Were the Super Sons chosen before the story or did the story choose them?

Page from The Foxglove Mission

Art by Ile Gonzalez

These are the characters DC asked me to write about. I was intimidated. The son of Batman? The son of Superman? But I grew up with both Batman and Superman, so I eagerly jumped in!

You’ve created some amazing original characters in Candace, Tilly, and Avyrc. I was really happy to see Candace’s story expanding in The Foxglove Mission, and even Tilly having an expanded role. Can you tell us a little bit about these characters? For example, how did you choose Candace’s superpower? Why is Tilly’s superhero alter-ego Puppet Girl? And what makes Avyrc such a great villain for our team to go up against?

My wife and I have two daughters (grown now). I’m comfortable with such characters; I’ve witnessed so much success, drama, heartache, and redemption. We also have an adopted son from Kenya, and I’ve written about Kenya on my adult side of publishing, so when DC and I discussed Jon and Ian, I wanted to add a female character, and that became Candace. She has “elemental” powers of controlling weather, and working with birds. She is my Earth woman.

 You’ve written a lot of cool tech, such as the DHI and a lot of Batkid’s gadgets? What piece of tech from your books do you wish you could use?

I wouldn’t mind having a hovercraft!

Similarly, you’ve written a lot of cool supernatural powers? If you could choose a superpower, what would it be?

The power to eliminate all poverty and prejudice. I’ve looked on Walmart shelves, but it isn’t there. Yet.

I’ve read that you’re more of a plotter than a pantser. Can you tell us a bit more about what your writing process is like?

Stories are shaped in many ways. Two of the most common are: start with a situation; or outline. I fall into the outline group. I like to work with the puzzle pieces first, see where they fit and how to fit them together. It’s not for everyone, but it works for me.

What was your writing journey like? You’ve written for all ages. How did you get started writing for middle-graders?

My writing journey would take up a long dinner! Basically, it has come down to understanding it’s hard work; that stories aren’t written, they are rewritten; that stories are about character; and all the plotting in world won’t replace one terrific character. 

Peabody Headshot. Found on the press section of Ridley Pearson's website.


 What is the best piece of writing advice you’ve received, and what writing advice would you give to someone just getting started?

My writing advice: Read. Then read some more. When you do try writing, dedicate some small piece of each day (for me it’s 6-8 hours) to sitting in the chair and putting words onto pages. Don’t worry if they are perfect—there’s time to fix that.

What are you working on next?

I have a new Kingdom Keepers series publishing September of 2020. Working title: Kingdom Keepers 2.0. I’m halfway through a new graphic novel trilogy for DC called The Indestructibles. It’s an original series that I’m incredibly excited about. I think the first book publishes in 2020 as well.

 How can people follow you on social media?

Very carefully. (Twitter. Insta. Facebook. I’m not great at it; something I’m working on.)