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Category Archives: Fingerprints/Patterned Evidence

Is Fingerprint Analysis Becoming More Automated?

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Each person possesses their own unique fingerprint pattern. No two prints have ever been found to be the same. This includes identical twins, who have the same DNA profile but different fingerprints. Not sure why this is, but it is. This means fingerprints are the perfect tool for identification and comparison.

But fingerprint analysis has a problem. It is subjective, in that it depends on the skill and dedication of the examiner. Another important factor is the quality of the print obtained from a crime scene. Those done in the police station, where the suspect’s prints are rolled in ink or obtained by a digital scanner, are clean and clear for the most part. Each of the ridges is easily visible and all of the nuances of prints are readily apparent. But at the crime scene, criminals refuse to cooperate in that way. They leave behind partial, smeared, and unclear prints that make analysis difficult. They also leave prints on surfaces that aren’t the best for retaining latent prints.

This makes the examination process tedious, time-consuming, and difficult. But what if computer techniques could enhance an unclear or partial print to the point that it could be compared by the computer itself? This would narrow the choices and lighten the burden on examiners so they would have more time to focus on the details and make sure the print indeed matched or didn’t.

A new technique for automating fingerprint analysis is under development. It’s pretty cool and promises to be helpful.

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How Old Is That Fingerprint?

Fingerprint

Fingerprints are useful forensic science tools. They’ve been so for over 100 years. Mainly, it’s the pattern of the ridges on the fingertips that supply the useful information. We know that everyone has different fingerprints and we know that they do not change throughout the person’s life. This means that they are highly reliable sources for identification and for discrimination between two individuals. Law enforcement has employed this for years.

But several newer techniques and analyses allow investigators to go even deeper. The skin cells, that are part of a fingerprint, can often yield DNA. Chemicals in the print residue can sometimes reveal if the person has used or handled such substances as cocaine. Other analyses are underway that might make fingerprints even more useful.

One question that frequently plagues crime scene investigators is exactly when a print was laid down. This determination can make a huge difference. Let’s say that a print is discovered at a homicide scene and the primary suspect says that he had been at that location but that that had taken place a week earlier. Not on the day of the killing. Is he telling the truth? Or simply trying to throw the police off and make an excuse for the evidence they collected against him? It would be nice to know if the print was 24 hours old or seven days old.

Research is currently underway by Shin Muramoto and his colleagues and they reported their initial findings in a recent article in Analytical Chemistry. They discovered that a chemical found in fingerprints known as palmitic acid migrates away from the ridges at a predictable and consistent rate. By looking at this migration pattern they are able to determine whether the print is fresh or up to four days old. They are looking to extend this envelope to a longer period of time. But you can see, that even this level of discrimination could help—or not—- the suspect in the above scenario.

 

Q&A with Expanded Audio Discussions Now on the Suspense Magazine Website

Q&A with Expanded Audio Discussions Now on the Suspense Magazine Website

Check out the new posts John Raab of Suspense Magazine and I put together. Read the Q&As and listen to the expanded discussions. Hope each proves helpful for your crime fiction.

Can DNA Be Used To Identify Multiple Assailants In a Three Decade Old Rape?

http://suspensemagazine.com/blog2/2016/12/20/d-p-lyles-forensic-file-episode-1/

In 1863, Could An Autopsy Accurately Determine the Cause of Death?

http://suspensemagazine.com/blog2/2017/01/09/in-1863-could-an-autopsy-accurately-determine-the-cause-of-death-d-p-lyle-answers-this/

Can My Female Character Cause Her Pregnancy To Become “Stone Baby” By Shear Will?

http://suspensemagazine.com/blog2/2016/12/31/can-my-female-character-cause-her-pregnancy-to-become-stone-baby-by-sheer-will/

More to come.

Want more cool questions from crime writers? Check out my three Q&A books.

M&M 200X300

More Info and List of Included Questions

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More Info and List of Included Questions

MF&F 200X320

More Info and List of Included Questions

 

Will 3D Printed Fingerprints Unlock a Phone?

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Can someone’s fingerprint be reproduced by 3-D printing technology and if so can it be used to unlock a cell phone? This is intriguing science and currently Professor Anil Jain at Michigan State University is looking into developing this technology. One of the problems is that many cellphone fingerprint security measures require not only pattern recognition but a certain degree of electrical conductivity that is natural to human skin. How to reproduce this in a 3-D printed model is one of the hurdles Professor Jain must overcome. But it is intriguing and we will see how it all shakes out.

 

 

 

FORENSICS FOR DUMMIES Release Day

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Forensics For Dummies Updated 2nd Edition is now available.

Get it through your local Indie Bookstore or here:

Amazon: http://www.amazon.com/Forensics-Dummies-Douglas-P-Lyle/dp/1119181658

B&N: http://www.barnesandnoble.com/w/forensics-for-dummies-douglas-p-lyle/1013991421

 

Forensics For Dummies, 2nd Edition Coming Soon

 

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Just got the new cover for Forensics For Dummies, 2nd Edition.

It will be released from Wiley on 2-29-16

Pre-Order now

 

Stupid Criminals: Man Attempts to Gnaw Off His Fingerprints

Damaged Print

If you have a record or an outstanding warrant or two, you might not want the police to ID you when you’re arrested for driving a stolen vehicle. I truly hate days like that. But, what to do? Maybe just gnaw off your fingerprints and they won’t be able to determine your ID. Probably painful, and probably won’t work. It looks like Kenzo Roberts gave it a whirl (no pun intended) anyway.

And he’s not alone. Many folks have tried to alter their fingerprints with cuts, burns, scrapes, and other painful procedures. Even Public Enemy #1 John Dillinger tried. Besides having plastic surgery to alter his face, he also attempted to burn away his fingerprints with acid. That didn’t work either.

John Dillinger

John Dillinger

FROM HOWDUNNIT:FORENSICS

FORENSIC CASE FILES: JOHN DILLINGER

John Dillinger was one of America’s most notorious criminals, once named Public Enemy No. 1. In an effort to evade the cops, he underwent facial plastic surgery and tried to remove his fingerprints with acid. After his betrayal by the famous “Lady in Red,” Dillinger was shot dead outside Chicago’s Biograph Theater. Prints taken at the morgue proved that the dead man was indeed Dillinger. The acid had damaged only a portion of his finger pads, leaving enough ridge detail for matching with his prints on file with the police.

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