To make a fictional criminal real, writers have to know how real criminals think and how they operate. One area that writers can easily exploit is the use of “signatures.” This is a consistent (post-mortem)“mark” that killers often leave at the crime scene.
The concept of “signatures” was developed by FBI whose theories on this have remained fairly consistent for the last twenty years. Basically a “signature” is a very specific thing that the killer does to his victim’s body. He may leave the victim’s body posed in a particular way that later identifies the killer every time he strikes.
Ted Bundy, a serial killer, was known to use pink polish to paint the fingernails of his dead victims. Every time this “signature” occurred, law enforcement knew they were dealing with a specific killer.
Fiction writers can make these specific calling cards creepy and terrifying. There’s no limit to this. Criminal “signatures” can also be set up in a way for the killer to communicate with law enforcement like the D.C. snipers did. Most killers leave a “signature” for emotional reasons providing insight to their criminal minds. These clues can be used to further an investigation.
A secondary character trained to interpret “signatures” can have a strong impact on the providing law enforcement on what type of killer is running loose. These interpretations can be anything a fiction writer wants them to be. Just the fact that the writer is using the concept of “signatures” makes the fiction more credible.
FBI profilers have long said that to catch a killer you have to study their art.
“Fiction on top of reality is like icing on a cake.” Lucinda Schroeder
PS: My true crime book “A Hunt for Justice” will be profiled on the Travel Channel on Feb. 21 at 9:00 ET. The series is called “Hidden Cities” and the city being profiled is Anchorage.
Lucinda D. Schroeder is a retired federal agent with 30 years of experience. She holds a degree in Criminology and is the author of “A Hunt for Justice.” Schroeder is a Savvy Instructor on crime related topics. http://www.ahuntforjustice.com