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Category Archives: Forensic History

Guest Blogger: Daphne Holmes: How DNA Testing Helps Determine Paternity

DNA

 

How DNA Testing Helps Determine Paternity

The impetus for determining the paternity of a child likely dates back to the most primitive tribal cultures. Particularly in patriarchal cultures where females were regarded as the property of males, it was deemed important to ensure that a man’s “property” had not been shared, and that the virtue of the female was beyond question. As societies became more sophisticated, the need to establish paternity became as much an economic issue as a moral one. In modern cultures, paternity testing is used primarily to establish whether or not a man is responsible for providing financial support to a child, as well as determining whether the child carries any of the father’s genetic predispositions for health challenges.

Physical appearance – In more primitive cultures (some of which continue to flourish), the objectives behind determining the paternity of a child were culturally and/or emotionally based. If a child was born who lacked identifying characteristics of either parent, it was frequently assumed that the father was someone other than the woman’s mate. The repercussions to the mother were quite severe, often culminating in her death. Unfortunately – especially for the women – the comparison of obvious physical traits was highly subjective, and many women suffered dire consequences, even if their husband/mate was indeed the biological father.

Blood typing – With the early 20th century discovery that different individuals had different blood types, and the recognition in the 1920s that those blood types were genetically inherited, a more accurate means of determining paternity came into common use. It was discovered that by comparing the parents’ blood types, it was possible to determine the most likely blood type of the child. While this was admittedly a step above the “he has his father’s eyes” paternity test, it was still only about 30% accurate.

Serological testing – It was discovered in the 1930s that specific proteins not considered during blood typing could establish the presence of genetically inherited antigens that would more accurately identify the child’s biological father. Unfortunately, serological testing only improved the accuracy of paternity testing to about 40%. Hardly conclusive evidence.

Tissue typing – In the 1970s, the human leukocyte antigen (HLA) was discovered in abundance within white blood cells. When samples of this genetically inherited antigen taken from the mother and child were compared to the sample taken from the father, paternity could be established with roughly 80% accuracy. While this was a significant improvement over previous methods, the collection procedure itself was unpleasant, and the size of the sample required made it hazardous to the child, particularly if the child was less than six months old. Obviously, more work needed to be done.

DNA testing (RFLP) – In the 1980s, the technique called restriction fragment length polymorphism (RFLP) was discovered that looked at a significantly wider spectrum of variables in the blood than had been analyzed with earlier techniques. It was discovered that the offspring of two parents would have half the unique characteristics of each parent. This technique elevated the accuracy of paternity testing to the level of statistical certainty. Unfortunately, the amount of blood required for accurate sampling was, like tissue sampling, large, posing potential problems for the child. In addition, the potential for genetic mutations in the child could render a false negative, indicating that neither the woman or the man was the child’s biological parents. For these reasons, RFLP testing has been all but abandoned.

DNA Testing (PCR) – By the 1990s, the RFLP testing was replaced by the polymerase chain reaction (PCR) technique. This technique involves the computerized replication of DNA collected from even a minuscule sample that is collected anywhere on the individual’s body, then comparing the subjects’ profiles. In addition to requiring a very small sample (typically via an oral swab), the subject is not submitted to discomfort as in earlier test techniques, and the computerized analysis takes far less time, while still providing accuracy at the level of statistical certainty, 99.99%.

Author: Daphne Holmes contributed this guest post. She is a writer from www.ArrestRecords.com and you can reach her at daphneholmes9@gmail.com.

 

 

Cat DNA Solves Another Homicide

TINKER

TINKER

 

Tinker doesn’t look like a snitch. But then again, neither did Snowball. Snowball is a very famous cat. It was Snowball’s DNA that led to the solution of a 1994 murder and it represented the first time cat DNA had been used to solve a crime.

From HOWDUNNIT: FORENSICS:

FORENSIC CASE FILES: SNOWBALL THE CAT

In 1994, Shirley Duguay of Prince Edward Island disappeared. A few days later her corpse was discovered in a shallow grave along with a leather jacket, which was soaked with her blood and dotted with white cat hairs. Her estranged husband, Douglas Beamish, owned a white cat named Snowball. DNA in blood taken from Snowball matched that of the cat hairs found at the burial site, proving that those hairs came from Snowball and no other white cat. Beamish was convicted, marking this case the first time that animal DNA was used to gain a conviction.

Tinker has now followed suit in a very interesting case from Britain.

 

Howdunnit200X267

 
 

The Writers Forensics Blog: 100 Top Websites to Bookmark

The crew over at FornesicScienceDegrees.org have listed The Writers Forensics Blog as one of their Top 100 Websites to Bookmark, which they describe as a “list of great sites to present practical, real-world information on the subject.” Many great sources here.

Thanks. I’m flattered.

 

 

Crime & Science Radio: The Body Tells the Tale: DP Lyle and Jan Burke Interview Dr. Bill Bass and Jon Jefferson

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The Body Tells the Tale: DP Lyle and Jan Burke Interview Dr. Bill Bass and Jon Jefferson

Join DP Lyle and Jan Burke as they explore the world of death, corpses, and decay with Dr. Bill Bass and Jon Jefferson. Dr. Bass is the founder of the University of Tennessee Anthropological Research Facility, the so called Body Farm. Jon Jefferson is a journalist, writer, and documentary film maker. Together they write fiction as Jefferson Bass. This will be a lively, or is it deadly, interview.

LISTENhttp://www.blogtalkradio.com/suspensemagazine/2013/11/20/crime-and-science-radio–jon-jefferson-and-bill-bass

LINKS:

The Body Farm-Wikipedia: http://en.wikipedia.org/wiki/Body_farm

Tour The Body Farm: http://www.jeffersonbass.com/videos.html

Video Tour of The Body Farm: http://www.youtube.com/watch?v=GSDCiOW81mk

WBIR Interview: http://www.wbir.com/news/article/139066/190/Your-Stories-Dr-Bill

JeffersonBass Website: http://www.jeffersonbass.com/index.php

Death’s Acre: Inside the Legendary Forensic Lab the Body Farm Where the Dead Do Tell Tales: http://www.amazon.com/Deaths-Acre-Inside-Legendary-Forensic/dp/0425198324

Metro Pulse: The Cult of Forensics Expert Dr. Bill Bass: http://www.metropulse.com/news/2009/feb/25/cult-forensics-expert-dr-bill-bass/

Peter Breslow’s 2004 NPR Profile of The Body Farm: http://www.npr.org/templates/story/story.php?storyId=1906569

Taphonomy-Wikipedia: http://en.wikipedia.org/wiki/Taphonomy

 

Eyes of the Beholder: An Old Myth Resurfaces, Sort Of.

eye-reflection

A century ago it was widely believed that the image of a killer was forever imprinted in the eyes of the victim. Sort of stamped on their retinas. This has been termed Optography and was a fiction staple in the 1800s and early 1900s. Of course, this isn’t the case. Not possible. Not yet, anyway but who knows what the future will hold.

However, in some situations a photo of the victim just might retain the killer’s image and this might be useful in tracking down the bad guy.

 

Crime and Science Radio: The Infancy of Toxicology: Interview with Deborah Blum, Author of The Poisoner’s Handbook

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DP Lyle and Deborah Blum, author of the critically acclaimed book THE POISONER’S HANDBOOK, discuss poisons, old and new, and the origins of forensic toxicology. Meet Charles Norris, New York City’s first ME, and Alexander Gettler, The Father of Forensic Toxicology, and walk with them through Jazz Age New York and the birth of forensic toxicology. Learn about poisons such as carbon monoxide, chloroform, arsenic, thallium, and many others.

LISTEN: http://www.blogtalkradio.com/suspensemagazine/2013/09/17/crime-and-science-radio–the-infancy-of-toxicology

LINKS:

Deborah Blum: http://deborahblum.com

Ethanol: http://en.wikipedia.org/wiki/Ethanol

Methanol: http://en.wikipedia.org/wiki/Methanol

Carbon Monoxide (CO): http://en.wikipedia.org/wiki/Carbon_monoxide

Arsenic: http://en.wikipedia.org/wiki/Arsenic

5 Classic Poisons and the People Who Used Them:

http://mentalfloss.com/article/23174/5-classic-poisons-and-people-who-used-them

Famous Poisonings, Real and Fictional: http://en.wikipedia.org/wiki/List_of_poisonings

Deadliest Poisons in History: http://io9.com/5942161/the-deadliest-poisons-in-history-and-why-people-stopped-using-them

Forensic Toxicology: http://en.wikipedia.org/wiki/Forensic_toxicology

Crime Library: Forensic Toxicology: http://www.trutv.com/library/crime/criminal_mind/forensics/toxicology/index.html

Poison and Progress: WSJ: http://online.wsj.com/article/SB10001424052748703699204575016971709814644.html?mod=WSJ_latestheadlines

Thallium Poisoning: http://en.wikipedia.org/wiki/Thallium_poisoning

Facts About Thallium Poisoning: http://www.medicinenet.com/script/main/art.asp?articlekey=79810

Mathieu Joseph Bonaventure Orfila, The Original Father of Toxicology: http://www.nlm.nih.gov/visibleproofs/galleries/biographies/orfila.html

Dancing With Black Widow Spiders: http://www.nytimes.com/2013/09/17/science/dancing-with-black-widows.html?_r=0

 

 

Ten Most Common Forensic Mistakes in Fiction

Ten Most Common Forensic Mistakes in Fiction: A fun Big Thrill interview with Jan Burke and I:

http://www.thebigthrill.org/2013/10/special-to-the-big-thrill-10-most-common-mistakes-in-fiction-regarding-forensics-by-d-p-lyle-jan-burke/

 

Crime and Science Radio: The Science of Sherlock Holmes

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Tomorrow, Saturday, 9-21-13, at 10 a.m. Crime and Science Radio presents:

The Science of Sherlock Holmes: Jan Burke and Leslie Klinger

Leslie Klinger is a Holmes expert of the first order. His THE NEW ANNOTATED SHERLOCK HOLMES is one of the most highly regarded studies of Holmes and his creator, Sir Arthur Conan Doyle.  What influenced Holmes’s scientific and investigative methods?  And what influence has Holmes had on forensic science and criminal investigation?

DETAILS and LINKS

LISTEN

 

Forensic Science and the Microscope

Without the microscope, there would be no forensic science. At least it would look nothing like it does today. When father and son Dutch lens makers Zaccharias and Hans Janssen discovered that lining up several of their spectacle lenses in a hollow tube would magnify any object viewed, they could never have imagined how their discovery would change the world. When Anton van Leeuwenhoek, the Father of Microscopy, perfected this design and incorporated it into his studies of biology and medicine, he too never imagined the invisible world he would enter. Science and medicine would never be the same and the gateway to modern forensic science was opened.

 

Microscope

 

The forensic science disciplines of blood analysis, firearm comparisons, trace evidence (hair, fiber, paint, etc.) examination, took mark interpretation, and even document examination regularly employ various types of microscopy.  HERE are some examples.

 
 

Marilyn: Suicide, Accident, or Murder?

 

In yet another great article titled “Marilyn’s Forensic Legacy” by Dr. Katherine Ramsland in Psychology Today, she addresses the death of Marilyn Monroe, a death that has remained controversial for half a century. Here Katherine addresses the psychological autopsy, an often useful tool in cases like this.

 
 
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