Showing posts with label fingerprints. Show all posts
Showing posts with label fingerprints. Show all posts

03 August 2023

CSI Auckland


I’ve never written a story that involved forensics. Sure, I’ve mentioned fingerprints, crime scenes, and DNA, but only in simple, blink-and-you'd-miss them sentences. I've never dug down into the nitty gritty of how a fingerprint is lifted or DNA is swabbed. I've never hung a plot on forensic science.

My avoidance of this realm of crime fiction writing has been plain and simple: I have had no idea. Also, only a handful of my stories have featured a police detective in the protagonist seat. I've never yet written a police procedural.

I could have YouTubed these CSI things, I guess. I'm no stranger to the Tube and have spent quite some considerable time learning how to pack a pipe, hot-wire a car, become an RA (Royal Academician), and so on. Honestly, if you can think it, there's probably a YouTube video for it (and for many things you probably don't want to think of).

Write what you know—

… the mantra and T-shirt slogan of all writers. And if you don't know, then stay away from it. Which is a double-edged sword for us crime writers--we write about people murdering people. I, for one, can report I have no practical experience in that sort of thing. Which reminds me of an excellent New Zealand novel that explores the premise. Paul Cleave's psychological thriller, Trust No One (2016 Niago Marsh Award winner for Best Crime Novel).

Anyway, I've finally gotten some hands-on experience in crime scene investigating. Really, really good experience.

I went on a training course in forensic science here in Auckland with a handful of work colleagues (software). Team building, CSI edition. A four-hour, immersive masterclass in crime scenes: fingerprints, shoe prints, blood splatter, trace evidence, and DNA. Our teacher was the real deal--

an actual CSI professional, fully qualified, with 32 years' experience (Scotland Yard and New Zealand Police). 

We examined a simulated crime scene (a life-size mannequin/dummy for a dead body), replete with murder weapon, shattered skull, blood splatter, and a roomful of clues. We budding Poirots and Marples were kitted out in proper crime scene PPE: scene suit, gloves, and blue booties that slipped on over our shoes. Working in teams of two, each team was provided with a hefty carry case full of field equipment needed for gathering evidence: fingerprint powder & brushes, lift tape & cards, tweezers, UV light, evidence pouches, scissors, swab sticks, distilled water, and so on.

We lifted and documented fingerprints from tins, cups, and a windowsill. We swabbed beer bottles for DNA and collected up fibres and a shoe print left by the murderer. We even determined the murderer was left-handed, based upon fingerprints left on the weapon and from the tell-tale flicks of blood on the wall. At the end, we ran the fingerprints we had collected through a computer database to look for a match. And we got one. All our teams of two correctly identified the killer from a pool of about thirty suspects.

Needless-to-say, the afternoon was not for the faint of heart.   

In addition to the hands-on experience, we also learned a lot about the history of forensics. Forensic, from the Latin forēnsis, meaning "of or before the forum." Back in ancient Rome, criminal cases would be decided based upon the evidence presented by the accused and the accuser. Whoever of the two presented the best argument and delivery would win.

We learned about Edmond Locard, the father of modern forensic science and criminology. He set up the first crime scene investigation laboratory in 1910 and pioneered many of the CSI methods still in use today. He also coined Locard's Exchange Theory, which is: Every contact leaves a trace. That's a handy piece of theory to remember. Writer Trivia: Georges Simenon is known to have attended some of Locard's lectures, circa, 1919. 

I'm not, nor will ever be, a hardcore forensics writer, but having a better understanding of the processes will certainly lead to its inclusion (in more depth) in my future stories. 

Tell me if you have something similar in your town up there in North America. Do the FBI or RCMP run courses like these?




Where we went:

Forensic Insight Ltd.

Something I prepared earlier. An article I wrote back in 2014 about fingerprints and an infamous Auckland robbery/murder. 




www.StephenRoss.net

09 April 2023

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.

14 August 2022

Fingerprints: Not So Elementary


Can a character in a mystery and crime novel have no fingerprints or altered fingerprints? This would make for a fascinating plot twist.

Fingerprints are used to identify people because each one is unique. Formed during pregnancy, fingerprints remain the same throughout life.

Fingerprints are also usually a durable identifier. In one famous case, a gangster in the 1930s, John Dillinger, tried to destroy his fingerprints by burning his fingertips with fire and acid. In the end, his skin regrew and his fingerprints were still intact.

However, details on fingerprints can be temporally changed

Some jobs, such as bricklayers, dishwashers and those who work with chemicals such as calcium oxide, may lose some details in their fingerprints but the ridges grow back once these activities stop.

Some medical conditions can impact fingerprints temporarily. Skin diseases such as eczema or psoriasis may cause temporary changes to the fingerprints, but upon healing the fingerprints will return to their original pattern.

Other medical conditions can leave people with no fingerprints at all.

A genetic disorder, adermatoglyphia, causes a person to have no fingerprints. Scleroderma is a disease associated with changes in skin elasticity, hardness, and thickness and eventually make a patient with scleroderma a “fingerprintless person”.

Some people treated for breast or colon cancer with the chemotherapy drug capecitabine may have a side effect called “hand-foot syndrome,” which sometimes can lead to loss of fingerprints.

fingerprint

What about a criminal who wants to change their fingerprints? One interesting option is surgical, “using plastic surgery (changing the skin completely, causing change in pattern – portions of skin are removed from a finger and grafted back in different positions, like rotation or “Z” cuts, transplantations of an area from other parts of the body like other fingers, palms, toes, soles.”

There’s an interesting case proving this actually works. A woman used this surgical method, “skin from her thumbs and index fingers were reportedly removed and then grafted on to the ends of fingers on the opposite hand. As a result, Rong's identity was not detected when she re-entered Japan illegally.”

Maybe we are entering a whole new era where we now have the knowledge that fingerprints aren’t as reliable as they once were, can even be changed and we now could have new plots twists.