Thursday, April 10, 2014

Forensics in Your Plotline: Information for Writers

Amanda Knox reacts at the announce of the verd...
Amanda Knox reacts at the announce of the verdict of
her appeal trial in the Meredith Kercher' murder
 (Photo credit: Beacon Radio)
Amanda Knox has probably learned more about forensics than she probably ever thought or hoped she would. But her case in Italy makes a very interesting point. While specific laws change from region to region - country to country, what constitutes good science does not. 
Video Quick Study (1:26)
Video Quick Study (2:31) rape case thrown out over tainted forensic evidence

Forensics is a science; specifically, the application of science to the law. It is the application of scientific techniques developed through the scientific method that produces data. Are these 100% accurate and dependable results? No. They are not. They are within a scope or continuum - the data falls on a line of probability. When DNA results are offered, it usually reads as 98.99% chance of accuracy (and even those results are based on some pretty weird location generality tables). Nothing is 100%. This is an excellent way to twist your plot line.

I remember distinctly reading about a case where the body of a baby was hand-carried to the coroner for autopsy. Based on the coroner's findings, the mother was convicted of murder and sent to prison for life. Decades later when the officer was diagnosed with terminal cancer, he admitted that he had dropped the baby's body down a long marble staircase. Also, the person who had performed the autopsy had failed to document body damage that had occurred premortem versus postmortem. When these aspects came to light a second trial was held and the woman found innocent.

Forensics is processed by humans. Humans make mistakes. Mistakes effect lives - and plot lines.  

When you see a forensic scientist on the witness stand they will:
* Explain what they did in terms of collection and analysis and
   why (process)
* Offer an interpretation of the results (expert testimony)
* Explain how they arrived at their interpretations
* Explain what conclusions can and cannot be drawn. For example
   in the Casey Anthony case the forensic scientist indicates that
   hair is not a source of positive identification. 
    Video Quick Study (4:17)
   Video Quick Study (10:19) How reliable is forensic science?

 (Photo credit: Wikipedia)

On occasion, forensics scientists will run experiments and try to collect data to help inform their testimony for a specific case.
Video Quick Study (2:10) 

And sometimes the scientists perform forensic experiments to inform future crime scenes. The Body Farm is an anthropological research center, for example, that sets up various scenarios for understanding how bodies decay. 
Video Quick Study (graphic in nature - 5:17) 

But it is important to note that not all forensic cases have to do with death. They can be anything from questioned document cases 
(Questioned Document Blog Article) to drug cases (Blog links to Illegal Drugs 101 and Toxicology Blog) and so forth.

Think about your crime scene as one great big science experiment.
1. There is an observation: "Hey, 
potd 4 17 12 - Forensic 497 final exam
potd 4 17 12 - Forensic 497 final exam (Photo credit: pennstatenews)
    look Harvey, I found
    a foot!"
2. There is a hypothesis: 
    "Someone must
     have been murdered!"
3. There is data gathering 
    (blog article CSI 101)
4. There is data analysis by
    various forensic experts
5. Conclusions are drawn. If the
    conclusion supports the hypothesis
    then you're ready to support a case in court. If the results do
    NOT support the hypothesis, then you have to start again with a
    different hypothesis.

Video Quick Study (7:33) Lack of reliable/valid research in forensic

Here it is in a handy-dandy flow chart if that helps:

English: Flowchart of the steps in the Scienti...
 Scientific Method (Photo credit: Wikipedia)

English: A forensic scientist at the U.S. Army...
 (Photo credit: Wikipedia)

When you are plotting your story, the analysis section is where you can twist the status quo. "The red toe-nail polish and dainty size did not hold up to DNA evidentiary review - this is not a woman after all!"

Now your inspectors have to start back to square one with the formulation of a different hypothesis.

See how this article influenced my plot lines in my novella MINE and my novel CHAOS IS COME AGAIN.

Thank you so much for stopping by. And thank you for your support. When you buy my books, you make it possible for me to continue to bring you helpful articles and keep ThrillWriting free and accessible to all.


  1. The third paragraph of the article certainly didn't make me feel any better about the justice system.

  2. Thanks for explaining the intracies of forensics...I'll see how you use it in "Mine" which is still free on Kindle

  3. Where can I find historical forensic methods, for instance in the fifties or earlier?