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Category Archives: General Forensics

Guest Blogger: Juan Dillon: Sherlock Holmes: Forensic Science Pioneer

Holmes

 

There are very few characters that have managed to assume a personality as pronounced as that of Sherlock Holmes. Even though he was a fictional character created by Sir Arthur Conan Doyle, Holmes was and still is often given the same respect that one gives to a real person. Apart from infusing life into his characters, Doyle was a visionary as well. He created this amazing character that solved crimes with panache and used methods that would be adopted in the field of law making only decades later. Forensic science was not even in its infancy when Holmes solved all those mysteries. When Doyle wrote Holmes, the situation was such that it required eyewitness accounts and ‘smoking gun’ evidence to convict a murderer. It was very easy for murderers to roam scot free as there was practically no evidence against them.

Holmes used fingerprints, blood stains and chemistry to zero in on his suspects. It was fascinating because these methods were not in prevalence at that time. In many ways he has contributed to the existence of the modern detective. Holmes used blood splatter patterns and bullet trajectory analysis to solve some of his cases. Every forensic detective today has a lot to learn from Holmes when it comes to toxicology. There were many cases where Holmes used scientific methods that involved chemical analysis and even analysis of handwriting. One of the biggest contributions to the world of forensic medicine by Holmes is the ‘exchange principle’ according to which when two things come into contact with each other, one leaves a trace on the other.

The ramifications of the exchange principle were enormous. This means that cases could be solved years or even decades after they were committed. There are instances of how people were exonerated years after they were erroneously imprisoned. There have also been cases of how cases were solved years later and the culprits brought to book. This was possible only through the methods made famous by Holmes. Poisoning was one of the most popular methods of murder in those times and the reason for that was because it was virtually impossible to detect many kinds of poison with the technology available at that time. Holmes would use scientific methods to check the presence of poison in corpses and detect whether a death was indeed natural or unnatural.

In fact there were a few avid readers of Doyle who became so fascinated with the world of forensics that they even set up laboratories for the purpose of research. A Frenchman named Edmond Locard built a forensics lab 23 years after Doyle envisioned a similar one in one of his books. In his lab he kept samples of soil, hair and mineral fibre. This was perhaps the first ever lab that eventually evolved into the state-of-the-art labs that are used by Scotland Yard or FBI. Holmes was also obsessed with something that has now become a science of sorts. He used to analyse shoe prints to solve many of his cases and now that is called Gait analysis. He was also the person who came up with the idea of using dogs to track criminals. He was aware of the ability of a dog’s keen sense of smell way before his contemporaries.

The use of footprints, fingerprints, handwriting etc were a few innovations that can be attributed to Dolye’s intrepid detective. He even did decryption of ciphers, a science that would not be developed even decades after Doyle’s death. It can be said without doubt that Sherlock Holmes, if he was a real human being would have been the world’s first ever forensic scientist. And the credit to that goes to his creator, the visionary called Sir Arthur Conan Doyle.

Author Bio: Juan Dillon is a freelance writer and currently working as a review developer at EssaysOrigin.com, and online platform for customers to choose best essay writing services by evaluating the professional reviews on various companies. He loves the profession as it’s also covers some sort of intellectual findings while working on review creation.

 

Can Odor Reveal the Time Of Death?

One of the most important determinations that the medical examiner must make in any death investigation is the Time Of Death (TOD). This alone might help solve a homicide. Who had the motive, means, and opportunity? The time of death relates to the opportunity. If the death occurred while the primary suspect was in another state or had a solid alibi, then he moves down the suspect list. On the other hand, if the TOD was determined to be a time frame where he was in the neighborhood, then he remains a viable suspect.

The ME uses many techniques to help estimate the TOD. Check out this ARTICLE for a brief overview of these techniques. One of the methods he employs is the degree of decay that has occurred. He must take into account the environmental conditions near the corpse and then must make a best estimate as to how fast the decomposition process would have advanced under those conditions. This is always a best guess, as is the case with each of the techniques he employs.

When a corpse decays it undergoes a chemical decomposition and this process releases many volatile organic compounds (VOCs) into the surrounding air. These compounds are at least partially responsible for the odor of decay and they tend to be released in a predictable pattern as the decay process progresses. What if these VOCs could be sampled and used as a more scientific method for determining the Post Mortem Interval (PMI)? That is, the time since death.

Research is currently underway to assess this technique. Using the combination of gas chromatography and mass spectrometry (GC/MS), researchers have found that these volatile chemicals can be trapped and analyzed. Hopefully this technique will prove to be useful in narrowing down the TOD. We’ll see.

 

Gas Chromatograph

Gas Chromatograph

 

 

 

Crime and Science Radio: The Skeleton Crew: A Conversation with Deborah Halber

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The Skeleton Crew: A Conversation with Deborah Halber on the Amateurs Who Are Finding the Missing and Solving Cold Cases

For decades, all across the United States, tens of thousands of missing persons cases have grown cold. At the same time, a mounting number of unidentified remains have been discovered and have been stored in coroner’s offices or buried in potter’s fields. But the Internet has been changing all of that. We talk to Deborah Halber, about some of the challenges and changes in the world of the unidentified dead and those who try to name them.

BIO: Deborah Halber started out as a daily newspaper reporter, then turned to the dark side to do public relations. She worked as a writer and editor for Tufts and as a science writer for MIT, where she chronicled everything from quantum weirdness (that’s the technical term) to snail slime. A freelance journalist since 2004, her writing has appeared in The Boston Globe, Inked, Technology Review, and Symbolia. Her narrative nonfiction book, THE SKELETON CREW: HOW AMATEUR SLEUTHS ARE SOLVING AMERICA’S COLDEST CASES, is just out from Simon & Schuster. A member of the American Society of Journalists and Authors, Mystery Writers of America, Sisters in Crime, and the National Association of Science Writers, she lives near Boston in a house with a lot of former pets buried out back.

 

LISTEN: http://www.blogtalkradio.com/suspensemagazine/2014/06/29/crime-and-science-radio-with-deborah-halber

 

LINKS:

Deborah Halber http://deborahhalber.mit.edu/

NamUs: The National Missing and Unidentified Persons System http://namus.gov

National Center for Missing and Exploited Children http://www.missingkids.com/home

NOKR: The Next of Kin Registry http://www.nokr.org

Black and Missing Foundation http://www.blackandmissinginc.com/cdad

Clark County Nevada Coroner’s Office: Las Vegas Unidentified  http://www.clarkcountynv.gov/depts/coroner/unidentified/Pages/default.aspx

Provincetown Site for Lady of the Dunes http://www.provincetown-ma.gov/index.aspx?NID=618

Todd Matthews Tent Girl Site http://www.angelfire.com/tn3/masterdetective2/

Porchlight International http://z10.invisionfree.com/usedtobedoe/index.php?showforum=41

The DOE Network http://www.doenetwork.org

The Charley Project http://www.charleyproject.org

America’s Missing Adults http://americasmissingadults.com/

California State Missing and Unidentified Persons Unit http://oag.ca.gov/missing

Ohio Missing Adults http://www.ohiomissingadults.com/

WDAZ: Remains Found 31 Years Ago in Wyoming Identified as Missing Minnesota Native http://www.wdaz.com/content/remains-found-31-years-ago-wyoming-identified-missing-minnesota-native-0

People Magazine: Murdered Teen’s Remains Given to Her Family 46 Years Later http://www.people.com/article/philadelphia-missing-girls-jane-doe-identified-family

Story About The Skelton Crew by Deborah Halber in Time Magazine: How to Solve a Murder With Just Your Computer http://time.com/2973705/how-to-solve-murder-with-computer/

 

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.

 

 

Crime and Science Radio: Dealing With the Dead: A Life in the Morgue: In Conversation with Dr. Cyril Wecht

Join DP Lyle and Jan Burke as they welcome Dr. Cyril Wecht, internationally renowned forensics pathologist Dr. Cyril Wecht as we discuss his life in criminal justice and the numerous famous cases he has been involved with over his stellar career.

BIO: Dr. Cyril Wecht holds degrees in both medicine and law, receiving his MD degree from the University of Pittsburgh and his law degree from the University of Maryland. He holds professorships at the University of Pittsburgh and Duquesne University School of Law. He has published nearly 600 scientific articles, is on the editorial board of more that 20 medical-legal and forensic scientific publications, and had published several books on forensic science. His list of famous cases is a who’s who in medical-legal investigation.

 

CYRIL-WECHT

LISTEN: http://www.blogtalkradio.com/suspensemagazine/2014/03/07/crime-and-science-radio-with-special-guest-cyril-wecht-md

LINKS:

Dr. Wecht’s Website: http://www.cyrilwecht.com

Dr. Wecht’s books and videos: http://www.cyrilwecht.com/books.php

50 Years Later, Wecht Continues To Poke Holes in Report on JFK Assassination: http://triblive.com/news/allegheny/5017529-74/wecht-commission-specter#axzz2tuBTchS1

Dr. Cyril Wecht Believes Killers of JFK, RFK, MLK Had Help: http://www.vindy.com/news/2013/may/01/renowned-pathologist-makes-a-case-for-co/

Dr. Cyril Wecht Lectures on the JFK Assassination: https://www.youtube.com/watch?v=-muQL-QPKeM

Dr. Cyril Wecht on JFK Assassination: Let’s Uncover the Truth: https://www.youtube.com/watch?v=YtUL-BpZAu8

Crime Library: JonBenet: From Impressions To Book by Dr. Katherine Ramsland: http://www.crimelibrary.com/criminal_mind/forensics/cyril_wecht/6.html

Dr. Cyril Wecht Discusses Forensic Challenges of Cold Cases: http://www.wtae.com/news/local/allegheny/Dr-Cyril-Wecht-discusses-forensic-challenges-of-cold-cases/19648550

Dr. Cyril Wecht: The Benefits of Forensic Credentialing: http://www.pbs.org/wgbh/pages/frontline/criminal-justice/real-csi/dr-cyril-wecht-the-benefits-of-forensic-credentialing/

Cyril H. Wecht: What I Know: http://www.pittsburghquarterly.com/index.php/What-Do-I-Know/what-do-i-know-with-cyril-h-wecht.html

Dr. Cyril H. Wecht: Pittsburgh’s Polymath: http://www.popularpittsburgh.com/pittsburgh-info/pittsburgh-history/famous-pittsburghers/dr-cyril-wecht.aspx

 

Final-Exams

 

 

 

 

 

Bacteria and Time Of Death

bacteria1

 

 

One of the most important things the ME must determine in any death investigation is the time of death. This determination can support or destroy alibis and suspect and witness statements, and point the finger at certain individuals while directing it away from others.

The ME uses various techniques to make his “best guess” as to the victim’s time of death. Things like body temperature, rigor mortis, lividity, stomach contents, and a few other determinations. Unfortunately, most of these are only marginally accurate.

Here is an article I wrote on this subject: http://www.dplylemd.com/DPLyleMD/Art-Timely_death.html

Any tool that can help make this assessment more accurate would be welcome.

Researchers at Sam Houston State University’s Department of Biological Sciences are looking into just such a tool. Bacteria. Just as insects visit a corpse in a more or less predictable pattern, it seems that bacteria do also.

We’ll see how this pans out but it’s very interesting.

 

 

Crime and Science Radio: A New Lab, A New Approach to Forensic Science: An Interview with Dr. Max M. Houck, Director of the Washington D.C. Department of Forensic Sciences

Max Houck

 

Dr. Max M. Houck is an internationally-recognized forensic expert who has worked for the FBI Laboratory, at a medical examiner’s office, in the private sector, and in academia. His casework includes the Branch Davidian Investigation, the September 11 attacks on the Pentagon, the D.B. Cooper case, and the West Memphis Three case, among hundreds of others. He served for 6 years as the Chair of the Forensic Science Educational Program Accreditation Commission (FEPAC) and serves on other committees, including for Interpol. Dr. Houck has published widely in books and journals. He is a founding Editor of the journal Forensic Science Policy and Management and has also co-authored a textbook with Dr. Jay Siegel, Fundamentals of Forensic Science. In 2012, he was in the top 1% of connected professionals on LinkedIn. Dr. Houck lives and works in Washington, DC as the Director of the DC Department of Forensic Sciences (www.dfs.dc.gov).

LISTEN: http://www.blogtalkradio.com/suspensemagazine/2014/03/01/crime-and-science-radio-with-special-guest-max-houck

LINKS:

BOOKS BY DR. MAX HOUCK:

Fundamentals of Forensic Science: http://www.sciencedirect.com/science/book/9780123749895

Science of Crime Scenes:

https://www.elsevier.com/books/the-science-of-crime-scenes/houck/978-0-12-386464-2

Succeeding as an Expert Witness:

http://www.crcpress.com/product/isbn/9781420051629

OTHER LINKS:

Washington, DC Department of Forensic Sciences http://www.dfs.dc.gov

Photo gallery for Dept of Forensic Sciences http://dfs.dc.gov/multimedia/forensic-sciences-photo-gallery

Washington, DC Official Website http://dc.gov/DC

American Academy of Forensic Science http://www.aafs.org

Forensic Science Education Programs Accreditation Commission (FEPAC) List of Accredited Universities http://fepac-edu.org/accredited-universities

Strengthening Forensic Science in the United States: A Path Forward (National Academy of Sciences study, free download) http://www.nap.edu/catalog.php?record_id=12589

How Does Forensic Science Affect Your Life? http://crimelabproject.wordpress.com/how-does-forensic-science-affect-your-life/

National Forensic Science Technology Center http://www.nfstc.org

FBI Forensic Science Laboratory http://www.fbi.gov/about-us/lab

Forensic Magazine http://www.forensicmag.com

PBS Frontline: Waco: The Inside Story http://www.pbs.org/wgbh/pages/frontline/waco/

National 9/11 Pentagon Memorial http://pentagonmemorial.org

Crime Library: DB Cooper http://www.crimelibrary.com/criminal_mind/scams/DB_Cooper/index.html

 

 

Q and A: How Would the Time of Death Be Determined in a Corpse Found in Snow?

Q: In my story, the body of a young woman is found by cross-country skiers in high-mountain country. (Average temps in December: 20 degrees/low to 40 degrees/high;  elevation about 9000 ft.) If the person had been dressed in heavy clothes, and the body had been there about 24 hours, would it be completely frozen? Partially? Would there be any way to determine when death had occurred?

MT, Albuquerque, NM

Jack-Frozen

A: The corpse would be at least partially and could be completely frozen–perhaps with some of the deeper internal organs only partially frozen. It depends on the clothing, exposure, moisture, wind, etc. Also the old rule that whatever happens, happens comes into play here. So the freezing could be either complete or partial.

Under these conditions, rigor and lividity would be delayed to an unpredictable degree so these would be very crude indicators and not very useful in determining the time of death (TOD). Body temperature might be more useful—emphasis on might—but this would not be very accurate either. If the core body temp had reached the ambient temperature, this determination is of no use, since once the corpse reaches the ambient temperature it will remain stable at that temperature, making body temperature useless. For example, if the corpse reached the ambient temp after 18 hours then 24 hours would look like 36 or 48 as far as body temp is concerned.

But if the corpse hasn’t reached ambient temperature, core body temp can be used to estimate the TOD. Not very accurately but at least in the ballpark. Under “normal” circumstances, a body loses heat at about 1.5 degrees per hour, but this depends on many variables. Your scenario is definitely not “normal,” so temp would be lost more rapidly. Could be 2 or 3 or 4 degrees per hour if there is wind or cold rain for example. Let’s say the ME found the core temp was 40 with an ambient temp of 30. This means the body is still cooling since it has not yet reached ambient temperature. Let’s also say that in his experience he believes (educated guess at best) the body would lose about 3 degrees per hour under the circumstances he sees at the scene. If so, subtracting the measured corpse temperature (40 degrees) from the normal body temperature (98) and dividing by the rate of loss (3 degrees/hour) would yield the estimated TOD.

The math: 98-40 = 58; 58/3 = 19 hours.

Based on these calculations, your ME might conclude that the death occurred approximately 19 hours earlier, give or take a couple of hours.

Of course the major flaw here is that the actual rate of temperature loss might vary from his estimate so, despite the math, his assessment remains a best guess. He would likely suggest a broad range—maybe saying the TOD was between 16 and 24 hours earlier. That’s really the best he could do.

So your corpse could be partially or completely frozen and the time of death could be difficult to determine. Except for one more trick: stomach contents.

Let’s say the corpse is frozen so that temp, rigor, and lividity are of no help yet it was known that the victim had eaten a certain food at a certain time prior to his disappearance. It takes the stomach 2-3 or so hours to empty after a meal so if the ME found the undigested meal in the victim’s stomach and knew the time of this final meal from witnesses, he could then more accurately place the time of death as within 2-3 hours after that meal. Let’s say he had lunch around noon, went skiing, and was then found dead 24 hours later. If the ME found that last meal still in his stomach he might suggest that the TOD was between 1 and 4 p.m. the day before. This might be your best bet for narrowing down the TOD.

 
 

Crime and Science Radio: Inside the Los Angeles Regional Crime Lab: An Interview with Dean Gialamas

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This Saturday, February 1, 2014 at 10 a.m. PST join Jan Burke and DP Lyle as they welcome Dean Gialamas, Director of the Los Angles County Sheriff’s Department’s Crime Lab, to the show to discuss this unique lab, what it’s like be be a crime lab director, the new federal forensic science commission, and more!

Dean Gialamas is the former director of the Orange County Crime Lab, the current director of the LASD crime lab, and was recently appointed to the first-ever National Commission on Forensic Science.  He is a past president of the American Society of Crime Lab Directors, and the president-elect of the California Association of Crime Lab Directors.

The Los Angeles County Sheriff’s Department of Scientific Services is an ASCLD/LAB-International/ISO 17025 accredited laboratory that operates from 10 facilities and employs over 300 personnel.  It serves a population of six million residents and over 100 local, state, and federal agencies.

LISTEN

LINKS:

LASD’s Scientific Services

FBI Laboratory Services

The Crime Lab Project

How Stuff Works: How Forensic Lab Techniques Work

Forensic Science Timeline

Experts Named to National Commission on Forensic Science

Announcement of Formation of the National Commission on Forensic Science

LASD Scientific Services Bureau

LAPD Scientific Investigation Division

American Academy of Forensic Sciences

American Society of Crime Lab Directors

American Society of Crime Lab Directors – Laboratory Accreditation Board

International Association for Identification

California Association of Crime Lab Directors

Hertzberg-Davis Forensic Science Center

California Association of Criminalists

Dean Gialamas at NIJ 2010 on Backlogs as a False Metric

Forensic Science Education Programs Accreditation Commission

 

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.

 

 
 
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