Koalas and Crime Scenes

During my late-night-I-just-cannot-sleep internet wanderings I stumbled upon a surprising fact: koalas have fingerprints.

Well, that changed everything. I went from cannot-sleep to must-not-sleep. My childhood stuffy was a koala so I have a special attachment to these adorably cute fur-balls and, although my stuffy is long gone, this exactly how I picture her.

Armed with my trusty computer, I started grilling the internet for information. Here is how that conversation went:

Why do koalas have fingerprints?

The answer appeared to be, ‘back up a bit, Mary, because we first need to ask why do any animals - including humans - have fingerprints?’ “what would make fingerprints useful from an evolutionary standpoint?…while fingerprints may not build friction on their own, they may help maintain grip by working in conjunction with sweat glands… And fingerprints may also provide crucial sensitivity in our fingertips.”

So why are koalas the only non-primate with fingerprints?

“Koalas are famously picky eaters who seek out eucalyptus leaves of a specific age… koala fingerprints must have originated as an adaptation to this task…the friction and sensitivity fingerprints afford may help them simultaneously hang onto trees and do the delicate work of picking particular leaves and discarding others—but hopefully not near a crime scene.” 

This led me to an intriguing question: can koala prints mess up a crime scene?

“Oddly enough, the fingerprints of koalas are nearly identical to human beings, and even under a microscope, they are basically impossible to tell apart. The shape, size and ridge patterns are bizarrely identical, even moreso than the similarities between primate and human fingerprints. However, while human beings have “dermal ridges” on their entire fingers and across their palms, koalas only have fingerprints on the tips of their fingers, where the majority of their gripping force occurs.”

A visual on that: 

I simply couldn’t believe that they can be mistaken for human even on close inspection. But the internet continued relentlessly on this path:

“The loopy whirling ridges on koala fingers can not be distinguished from humans, even after a detailed microscope analysis. Koala fingerprints resemblance is even closer than the fingerprints of close human relatives such as chimps and gorillas.”

I remained unrepentantly sceptical and searched till I found this from Chantel Tattoli, a freelance journalist researching fingerprinting.

“In her research, she came across media reports of koala prints fooling Australian crime scene investigators. However, a NSW fingerprint expert told her the reports had been exaggerated.

"Anybody who is really a specialist in fingerprints can read the difference," Tattoli said.”

Since this is the only mention I found of koala fingerprints not being able to fool experts, I was sceptical of this as well.

What about primates? Their fingerprints aren’t as close to human as koalas, but are they similar?

“Gathering dust in police files is a dossier containing the fingerprints of the most unlikely criminal gang - half a dozen chimpanzees and a pair of orang-utans.

Their dabs were taken during police raids at the Ape House at London Zoo and at Twycross Zoo in Leicestershire. The operation, by fingerprint experts from Hertfordshire police, took place in 1975 at a time when there was growing concern over unsolved crimes. It concluded that chimp dabs looked exactly the same as ours, but did not link them to any specific offence.”

My late night conversations with the internet led to another conversation with my imagination - and hopefully yours as well: is there anything useful in this for a mystery writer? Maybe fingerprints at a crime scene of a koala or even a primate that baffle investigators? More believable if they’re partials? The problem is why would a koala be at a crime scene in the first place, because they’re law-abiding and not prone to fits of murderous rage? This character analysis comes from a close relationship with my childhood stuffy. Let’s assume the koala is innocent. Please. Maybe if the story is set in Australia or in a zoo, koala fingerprints could be found at the crime scene.