Category Archives: Guest Blogger

Guest Blogger: Forensic Psychologist Stefanie Stolinsky, PhD: Problem Gambling


Problem gambling is actually an obsessive-compulsive mental disorder. And although many people gamble without its becoming a problem, addicted gamblers find an excitement in gambling that they find nowhere else in their lives.  It is often referred to as a “high” or a “rush,” akin to taking a drug.  The partial reinforcement inherent in obsessive gambling is the fault of sometimes winning big, sometimes losing big and never knowing what’s going to happen next.  An animal will continue to press a lever if food comes down the pipe sometimes.

Getting help for someone who has a destructive gambling habit can be difficult.  Gamblers rarely want therapy on their own, though they may agree to it under family pressure.  Sometimes when a chronic gambler is sentenced for illegalities stemming from gambling debts, a judge makes therapy a condition of probation.  In a structured environment such as a rehab center, there is the advantage of starting therapy in a setting that removes the gambler from temptation.

But the best approach to therapy is a combination of behavioral techniques, focused on stopping gambling, and supportive therapy to help the gambler deal with the chaos gambling has brought to their life.  Therapy may be long-term and there are usually some relapses, but that does not mean that therapy is a failure if the gambler uses the slip as an opportunity to learn how to resist temptation.

S. A. Stolinsky
FierySeas Publishers


Stefanie Stolinsky is a licensed clinical and forensic psychologist.  She is the author of the acclaimed non-fiction book, ACT IT OUT: 25 Expressive Ways to Heal from Childhood Abuse, published by New Harbinger Publications, Inc. in 2002 and currently in its second edition with Praeclarus Press.  Dr. Stolinsky has written for over twenty years, having finished five mystery novels, numerous short stories (published in Sherlock Holmes Mystery Magazine) and two well-received plays.  She has worked extensively with abuse and trauma survivors privately and from the military.  She also works with those suffering from gambling addiction.  She has a private psychology practice in Beverly Hills and lives with her husband in Los Angeles.


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Posted by on October 13, 2016 in Guest Blogger, Medical Issues


Katherine Ramsland: What if Jack the Ripper Lived with You?

It seems that after many disturbing crimes, the family, friends, or neighbors, in shock at what happened, often say: “But he seemed so nice. So normal. We had no idea.”

Happens all the time.

My friend Katherine Ramsland addresses this in an excellent new blog post in Shadow Boxing on the Psychology Today site.




What if Jack the Ripper Lived with You? by Dr, Katherine Ramsland

An early Ripper tale depicts the role of denial in reframing the obvious.

I’ve long known about an early fictional story based on the murders attributed to Jack the Ripper, but only recently read it. The Lodger, by Marie Belloc Lowndes, was published as a short story in January 1911 in McClure’s magazine. Later, she lengthened it into a novella that focused on the female landlady. Alfred Hitchcock changed it somewhat to turn it into a film.

Reportedly, Lowndes was inspired by an anecdote she heard at a dinner party about an elderly couple who were certain that Jack the Ripper had lodged with them around the time of the murders late in 1888. During the Ripper spree, Lowndes had been a young aspiring writer. Although she was in Paris, not London, at the time, she followed the sensational news coverage. Years later, she used the unique context to write a story that drew out gender and class issues in London society. She also shows a keen eye for subtle psychological twists.

The plot is basic: The Buntings, an aging couple with financial problems, are overjoyed when a single man arrives and decides to rent several rooms. Without this stroke of good luck, they would have starved. The lodger, Mr. Sleuth, is an odd duck, but Mrs. Bunting can overlook this as long as he pays and doesn’t cause trouble. Her accommodating attitude foreshadows more dramatic allowances to come.

Mrs. Bunting attends to Sleuth, while her husband spends his time reading newspapers, especially when stories pop up about “The Avenger,” a Ripperesque killer of alcoholic women. Mr. Bunting has a friend on the police force, so he gets behind-the-scenes details. This also gives the author a chance to describe Scotland Yard’s Black Museum, founded in 1875.

Criminological museums popped up in several large cities during the late nineteenth century. Objects and pictures were exhibited to showcase theories about crime and its perpetrators. Into these museums went weapons, poisons, blood samples, fingerprints, hangman’s nooses, morgue photos, crime reconstructions, handwriting samples, police memorabilia, and even human remains.

Mrs. Bunting despises her husband’s obsession with the unsolved Avenger murders, but she begins to suspect that their lodger might be the guy. This is where the story’s genius lies. The more she discovers, the more she covers for him. She even ventures out to a coroner’s inquest – something only vulgar people did – to discover what the police actually know. (Great period detail!)

Mrs. Bunting knows the lodger has a satchel but she cannot find it when she cleans his rooms. She spots red liquid seeping from a locked cabinet, but accepts his hasty and implausible explanation. She begins to act in uncharacteristic ways, including lying to her husband. Each time she discovers something that implicates Mr. Sleuth as a killer, she tones it down.

In part, she needs to feel safe in her own home, and in part, she needs the money. If he’s arrested, she faces poverty.

In this tale you get some early criminal profiling (a “mission killer”), and even a glimpse of Madame Tussaud’s famous wax museum. But most interesting is the way Lowndes so subtly shows how anyone might accommodate the behavior of someone later unmasked as a serial killer.

I hear this question all the time. People just cannot believe that in the home of a serial killer there might be innocent parties. But it happens. Even if certain items or behaviors should seem sinister, denial is a powerful mechanism – especially when a personal investment in seeing things in a more flattering light is strong.

The best expression I’ve seen is in Lionel Dahmer’s memoir about his son, Jeffrey. When Jeff lived in his grandmother’s basement, she complained to Lionel twice about disgusting odors. Jeff had an innocent explanation: he experimented with chemicals on chicken parts from a grocery store. Lionel found a nasty-smelling liquid near the garbage cans that he thought was ordinary meat juice. Why would he have concluded that it was human blood?

“I allowed myself to believe Jeff,” Lionel mused in A Father’s Story, “to accept all his answers regardless of how implausible they might seem…. More than anything, I allowed myself to believe that there was a line in Jeff, a line he wouldn’t cross…  My life became an exercise in avoidance and denial.”

He accepted a stolen mannequin as a “prank”, a .357 Magnum as a “target pistol,” a charge of child molestation as an “accident,” and the request for a freezer as a responsible attempt to be economical. Who would have thought it was for dismembered body parts?

The Lodger sheds no light on the Ripper’s identity, but it does portray what can happen when bias and need infect our perception and beliefs.

Visit the original post:

And check out Katherine’s recent interview on Crime and Science Radio:




Guest Blogger: Anne Trager: Alchemy 101—Can You Make Your Own Gold?

Alchemy 101—Can You Make Your Own Gold?

Anne Trager, translator
The Lafayette Sword by Eric Giacometti and Jacques Ravenne

Can you actually make your own gold? I uncovered the truth recently while working on a fun thriller by Eric Giacometti and Jacques Ravenne called The Lafayette Sword. The plot has gold fever, Freemasonry, murders, and the quest for a stolen, priceless sword. It also has alchemy. It’s fiction, but to write it, the authors did a lot of research, and to translate it, so did I.

What exactly is alchemy?

Alchemy dates back four millennia, spans three continents (China, India and Europe), and includes a lot of symbolic mumbo-jumbo. But in short, it was part science, part magic.

Medieval European alchemy set out to make a substance called the philosopher’s stone—it was not actually a stone, but similar to wax in consistency. It was supposed to transform base metals into gold. Perfect for the greedy and power hungry, you may think. In fact, alchemy was more than a quest for a money-machine. It was also a symbolic journey of self-realization and the precursor to chemistry.

Magnum Opus

At the time, people thought everything was made up of fire, air, water and earth. If a common metal like lead was made of these elements, then gold was too. Thus, in theory, one could be transformed into the other.

The alchemical world view also included the idea of progression or maturation. Gold was considered the most mature metal because it had a perfect balance of these four elements. In some traditions, it also symbolized the most advanced stage in a person’s spiritual refinement. The transmutation of lead into gold was like the transmutation of the physical body into a higher energy—that is, becoming immortal.

The key was in the philosopher’s stone, which not only transformed metals, but also had healing powers, and was an essential ingredient in the elixir of life.

So, the alchemical Great Work, or Magnum Opus, was the process of working with the prima materia to create the philosopher’s stone. It ultimately led to gold, a perfect body and soul, and enlightenment—an enticing promise.


Not so fast. As an article in Scientific American states,

“Alchemists have often been dismissed as pseudoscientific charlatans but in many ways they paved the way for modern chemistry and medicine. The alchemists of the 16th and 17th centuries developed new experimental techniques, medicines and other chemical concoctions, such as pigments. And many of them ‘were amazingly good experimentalists,’ says Lawrence Principe, a chemist and science historian at Johns Hopkins University. ‘Any modern professor of chemistry today would be more than happy to hire some of these guys as lab techs.’ The alchemists counted among their number Irish-born scientist Robert Boyle, credited as one of the founders of modern chemistry; pioneering Swiss-born physician Paracelsus; and English physicist Isaac Newton.”

Isaac Newton, who was a Freemason and practiced alchemy throughout his life, even played an important role in the gold market. In 1696, he was appointed to the Royal Mint. At the time coin counterfeiting was rampant. He managed to recall all the coins in circulation, manufacture and issue new secure coinage and introduce the gold standard. Go Isaac!

Perhaps the most famous alchemist of all times was Nicolas Flamel, who figures in The Lafayette Sword, as readers follow his quest for the philosopher’s stone. The legend around him grew during the seventeenth century, when alchemy was all the rage, and continues to this day. He’s quoted in Victor Hugo’s Hunchback of Notre Dame, he figures in Harry Potter and the Philosopher’s Stone, he’s mentioned in The Da Vinci Code. (Now, that’s an odd combination of titles to have in one sentence.)

Yes, you can

Today alchemy is actually possible. We have the technology, and it’s been done. Nobel laureate Glenn Seaborg tranmuted tiny quantities of bismuth into gold in 1980. What you need, again according to Scientific American is: “a particle accelerator, a vast supply of energy and an extremely low expectation of how much gold you will end up with.” The current consensus is that it would cost way too much (a quadrillion dollars per ounce) to be worth it.

Find out more

¥ For an in-depth examination of gold from antiquity to modern times, read Peter Bernstein’s The Power of Gold: The History of an Obsession.

¥ The World Gold Council,, provides information about current prices, mining, supply and demand and research.

¥ For more about gold market manipulation, and the inspiration for the worldwide gold conspiracy in The Lafayette Sword: Gold Anti-trust Action Committee

¥ On the science of turning lead into gold:

¥ More on Newton: Newton and the Counterfeiter by Thomas Levenson

¥ More on alchemy:

Gold. Obsession. Secrets.


Eric Giacometti and Jacques Ravenne rank at the top of France’s best-selling thriller writers list. They owe their international renown to their series about the Freemason Inspector Antoine Marcas, which made its U.S. debut last year with Shadow Ritual. Now, The Lafayette Sword is available in English.

Following the murder of a Freemason brother, Antoine Marcas uncovers unsettling truths about gold and its power to fascinate and corrupt. A priceless sword is stolen and deaths ensue setting the Freemason detective on a case of Masons turned bad. A clue points to mysteries and conspiracy about elusive pure gold, launching a frantic, deadly race between two symbolic places—the Statue of Liberty and the Eiffel Tower. A captivating plot weaves alchemy and the Middle Ages into a modern-day thriller.

Web page:

Praise for the series

•“Vivid characters, evocative international settings, and a history darker than midnight. I highly recommend!” —Douglas Preston, #1 bestselling coauthor of the famed Pendergast series of novel

•“A race against the clock.” —Le Figaro

•“A superbly esoteric blend of history and adventure.” —Glenn Cooper, internationally bestselling thriller writer

•“Giacometti and Ravenne’s series kickoff has abundant visceral appeal.” —Kirkus Reviews

•“Brilliantly plotted and well researched.” —Le Parisien

The authors


Eric Giacometti studied biochemistry and genetics in Toulouse, France, before going into journalism. Then, at the height of his career as an investigative reporter, Eric Giacometti was contaminated by the thriller virus. His life took on another dimension: journalist by day, writer by night. In 2013, he left his full-time reporting job with a French daily newspaper to work freelance and write. He teaches journalism and writing.

Jacques Ravenne is a high-level French Freemason. He is also a literary critic, known for his work on the writers Paul Valéry, Yves Bonnefoy, Gérard de Nerval and Stéphane Mallarmé. In addition to his academic work, he was also a local elected official for a number of years, and contributes regularly to Freemason publications. He discovered the Marquis de Sade’s château in 1985, beginning a

long fascination with the man, which has resulted in an anthology of his correspondence and a novel based on Sade’s life.

Book Info:

Anne Trager
Le French Book
French books you’ll love in English!


Anne Trager is the founder of Le French Book, a publisher dedicated to hand-picking, translating and publishing top crime fiction from Europe. Their recent release The Lafayette Sword is by Eric Giacometti and Jacques Ravenne, who rank at the top of France’s best-selling thriller writers list. They owe their international renown (over 2 million copies sold) to their series about the Freemason Inspector Antoine Marcas, which made its U.S. debut last year with Shadow Ritual. Now, The Lafayette Sword is available in English. Following the murder of a Freemason brother, Antoine Marcas uncovers unsettling truths about gold and its power to fascinate and corrupt in a captivating plot that weaves alchemy and the Middle Ages in to a modern-day thriller. Find out more here. Or read an extended sneak preview here.


Father’s Unborn Twin Is the Genetic “Father” of His Son

A couple of years ago a happy couple in Washington welcomed a new baby boy. All was good until a paternity test showed that the father was not the father. Uh-oh. Well, it’s not really that bad. Turns out that genetic testing revealed the father was a chimera and the genetic testing was confused by his unborn twin’s DNA, which the father had absorbed in utero. Chimerism is an odd and interesting medical entity.


Greek Chimera

In Greek Mythology, the Chimera was a fire-breathing female that was part lion, part goat, and part dragon. Fortunately, human chimeras, which result from the combining of two or more human embryos in utero, are typically normal in every way—-except for that DNA stuff.

I’ve blogged and had Guest Bloggers comment on chimeras before:

Q&A: How Could My Sleuth Recognize a Chimera?

Guest Blogger: EE Giorgi: I Am My Mother’s Chimera. Chances Are, So Are You

Guest Blogger: Human Chimerism: Mindboggling DNA Tests Gone Wrong


Guest Blogger: Katherine Ramsland: Walk in My Shoes, Said the Serial Killer

Walk in My Shoes, Said the Serial Killer

By Katherine Ramsland

It’s easy these days to find quickie guides to forensic science and psychology. You have to look harder if you want in-depth details from experts. That’s why I like being interviewed for Crime and Science Radio with D. P. Lyle and Jan Burke. They’re both forensic professionals who are also writers. They ask good questions because they have extensive knowledge and experience.

I have a Crime and Science program coming up on August 13 regarding the writing of my two latest books, The Ripper Letter (a novel) and Confession of a Serial Killer: The Untold Story of Dennis Rader, the BTK Killer. (–science-radio.html) Since Confession will be published in early September, I’ve been asked a lot about it, which sends me back to the text again and again to relive the experience of working closely for five years with a serial killer.

A peculiar thing about me, and maybe this is true of other writers, is that I move so fast from one project to the next that I often forget what I’ve just written. Because the BTK book took much longer than most of my books (and since I’m still in touch with him), I recall a lot about the experience. Yet when I look through the pages, I’m surprised by how dense with information this book is.




It begins with my struggle to understand Rader’s codes, covers his “dark journey” from his point of view, and ends with my professional evaluation. As disturbing as many of his revelations were, it has been among the most interesting book-related experiences of my life (and I went undercover with vampires for over a year!)

First, let me say why this project took five years. Rader had signed over his “life rights” to his victims’ families, and they evaluated authors who asked for a shot at this project. I passed the test, because I planned to give Rader’s memoir serious treatment that would benefit law enforcement and the fields of criminology and forensic psychology. I also agreed that they should benefit financially.

Once approved, I had to read five years’ worth of letters and documents that Rader had turned over to the family trust in order to write a proposal. Then I had to convince my agent. There were many layers. All during this time, I guided Rader through his autobiography.

So, this book is not just a serial killer blathering on about himself. We’ve had books like that already. Instead, his narrative is structured with what we know from criminological research. I filled in the theoretical details and provided Rader with specific items to read and ponder. Rader did talk in detail about each of his murders, but he also described the factors that he believed weighed most heavily in his trajectory toward serial violence. He proved to have some interesting self-reflections.

Rader has counted over 100 letters to me to date, some of which were 20-30 pages long. He also talked with me weekly by phone, and drew explicit pictures from his fantasy life, providing a rare opportunity to get inside the mind of an organized, predatory serial killer who based his killing career on specific role models. His story, in his own words, is fascinating. Some readers have told me that it’s also frightening.

Because I listened to Rader and assisted him to view his “dark side” from various angles, including neuroscience (which fascinated him), he dove deep. It took nearly two years before he opened up in a way that I think is valuable for criminologists and psychologists, but he did manage it. We taught things to each other, which doesn’t happen very often in my world.

So, I’m pleased to have the opportunity to discuss it in a lively presentation with Lyle and Burke. A production of Suspense Magazine, Crime and Science Radio airs every other Saturday at 10 AM PT on Blogtalk Radio. It’s free!


NOTE: Join Katherine on CRIME AND SCIENCE RADIO as Jan and I welcome her to discuss her work on this amazing book and many other topics.

MORE INFO:–science-radio.html





Guest Blogger: Lisa Black: Everything Old Is New Again


My character, Cleveland forensic specialist Maggie Gardner, is unrealistic in one respect—she still spends a lot of time at her microscope looking at tiny bits of trace evidence, hairs, fibers, paint, and glass.

No one does that any more. Well, maybe Abby on NCIS, but she’s the most unrealistic forensic person on screen, even though she’s so cute we don’t care.

Sure, on old episodes of Dragnet you can see some nerdy guy in a lab coat explain how these pollen spores are only found in one quadrant of the city, but that art had already died before I started in forensics in 1994. We got spoiled by DNA, by ‘absolutely yes’ or ‘absolutely no’ answers. No one wanted to hear that this red nylon was ‘consistent with’ the suspect’s shirt, because they wouldn’t be hearing how many red nylon shirts were manufactured, how many were sold in this area, and while we’re at it let’s hack into Macy’s sales figures and find out who they were sold to. Unlike television, forensic labs do not have databases of all this information and would probably be violating a few important laws if they did. Nope, ‘consistent with’ was all you got. Take it or leave it.




They left it. Microscopic analysis became more or less a thing of the past. Forensic techs today wouldn’t recognize a pollen spore or know what to do with it if they did. Fibers are ignored. Hairs are examined only to screen out candidates for, well, DNA.

Imagine my surprise, then, when I peruse the latest Journal of Forensic Sciences and stumble on an article about using something called palynological scanning to rapidly evaluate suspect and victim testimony.




Palynology, it turns out, is a fancy name for…pollen. Pollen and spores and other ‘microscopic entities’ of trees, shrubs and herbs. No hairs, fibers or paint, but you get the idea. This analysis proved useful in some cases of rape or assault, in situations where the victim and suspect both contacted the ground and pieces of the ambient flora could attach to their clothing.




In one case the suspect said he and his victim engaged on a lawn behind a public building. The victim said he attacked in a heavily wooded area, the spot surrounded by beech, birch and sycamore trees. Each site had a distinct mix of items—palynomorphs– with complicated Latin names. The suspect didn’t deny that he had made contact with the victim so willingly gave up the clothing he’d been wearing at the time, and sure enough, all those little palynomorphs indicated that he had been in the woods and not on the lawn. This did not prove that he had committed the crime. It only proved that he had lied about the sequence of events, and that was sufficient to prompt a confession. Otherwise this case would have languished in an eternal hell of ‘he said vs. she said.’

Of course had this guy listened to legal counsel before he made a statement, he probably would have figured out to come up with an alternative, and innocent, reason to have been rolling on the ground near the crime scene, and all these spores would have been for naught. As it is, surely the defense will bring out statistics regarding the vast number of beech and sycamore trees in the area, perhaps in the suspect’s own neighborhood, and the idea that maybe he had been doing some gardening earlier in the week in that same pair of pants. This is why things like pollen analysis fell out of favor with the courts…but the spores are still out there, voluminous, distinct and quite concrete little buggers that will stick in all sorts of places one might wish they wouldn’t. So are hairs, fibers, and paint. Maybe ‘consistent with’ is all you can get out of them. But maybe, sometimes, that’s enough.

So in my books Maggie still looks at all this stuff because it’s more visible and visceral than yet one more DNA sample. Let’s face it—you’ve seen one cotton swab, you’ve seen them all. Bright clothing fibers are much more entertaining.

And this trace evidence will lead her down a number of roads—some of which, it turns out, she’d be better off avoiding.

Wiltshire et al. “A Rapid and Efficient Method for Evaluation of Suspect Testimony: Palynological Screening.” Journal of Forensic Sciences, Vol. 60, #6, Nov 2015, pp 1441-1450.


L Black

Lisa Black has spent over 20 years in forensic science, first at the coroner’s office in Cleveland Ohio and now as a certified latent print examiner and CSI at a Florida police dept. Her books have been translated into 6 languages, one reached the NYT Bestseller’s List and one has been optioned for film and a possible TV series.

Lisa’s Website:


that darkness cover


Hello! Just a quick note to let you know that my new book, That Darkness, is now available wherever books are sold!

It seemed like a typical week for crime scene specialist Maggie Gardiner–a gang boss shot in an alley, a lost girl draped over an ancient grave, a human trafficker dumped in the river–nothing all that out of the ordinary for the Cleveland police department as spring turns toward summer along the Erie banks. The methods are usual, the victims unsurprising–but when she notices a pattern, a tenuous similarity among the cases, she begins to realize that her days will never be typical again. How much of her life, her career, her friends, will she be willing to risk to do what’s right?

Jack Renner is a killer who does not kill for any of the conventional reasons…no mania, no personal demons. He simply wants to make the world a safer place. He doesn’t think of himself as a dangerous person–but he can’t let anyone stop him. Not even someone as well-meaning as Maggie Gardiner.

Maggie has the self-sufficiency of a born bit-of-a-loner. She works with a bevy of clever experts surrounded by armed police officers. She is both street smart and book smart, having seen the worst the city has to offer.

But Maggie Gardiner is not safe. And, until she can draw Jack Renner into the light, neither is anyone else.

Jeff Lindsay, author of the Dexter series, says: “Lisa Black always delivers authentic characters in riveting stories. That Darkness takes things to a spellbinding new level with a taut and haunting story that will stay with you long after you finish reading it.”

Publisher’s Weekly says: “The intriguing forensic details help drive the plot to its satisfying conclusion.”

“Black is one of the best writers of the world of forensics, and her latest introduces Maggie Gardiner, who works for the Cleveland Police Department. Her relentless pursuit of answers in a dark world of violence is both inspiring and riveting. Readers who enjoy insight into a world from an expert in the field should look no further than Black. Although Cornwell is better known, Black deserves more attention for her skillful writing – and hopefully this will be her breakout book.”– RT Book Reviews, 4 Stars (Top Pick)


Guest Blogger: Megan Inslee: My Love-Hate Relationship with Forensic DNA



What is the most important point to keep in mind when working with forensic DNA evidence?  There are probably a lot of answers to that question, depending on your experience and perspective.  I’ll let you in on my opinion for now, as a former DNA forensic scientist. One of the imperatives of working forensic DNA cases in this modern age is this: accepting that there are cases (many, in fact) that DNA can’t resolve.

Almost every time I testify, I’m asked “why might you not find DNA?” This is a good question, one which I usually answer with a fairly long list of possibilities, but it all boils down to three main points. 1. DNA may not have been deposited in the first place. Does this mean that the incident didn’t happen as reported by the victim or witnesses? Not necessarily – more on that a bit later.   2. Maybe too little DNA was deposited for the lab to test and identify. But can’t you guys detect even a few cells? More on that, later, too.  Or, 3. Perhaps DNA was deposited at an adequate level, but much of it was washed away or degraded over time. I saw a special on cold cases solved by DNA decades later – I don’t believe there’s anything you can’t do. Well, keep reading.

1. DNA may not have been deposited in the first place.

We’ve become so accustomed to DNA evidence being presented in criminal justice cases that we seem to need to take a collective step back to reflect on a case in which it just isn’t there.  It really depends on the scenario and the knowns of the case what this lack of DNA on an evidence item could mean.

The murderer doesn’t always cut herself on the knife and leave drops of her blood at the scene. The burglar may have kept his gloves on throughout the entire crime, never touching anything with a bare hand.  A child molester doesn’t always leave semen evidence for us to test.

And, of course, DNA may not be present on a tested evidence item simply because the scenario didn’t unfold the way investigators believed or the witnesses stated or the victim recalled.  Corroborating DNA evidence with reported scenarios is a tricky business, one which doesn’t always result in a resolution tied up with a big red bow.

2. Maybe too little DNA was deposited for the lab to test and identify.

Remember the days when crime labs couldn’t get DNA from anything smaller than a blood drop the size of a quarter?  And remember when, even when they started getting DNA from smaller samples, the odds of someone else having the same DNA profile was only one in several thousand?  Well, I don’t – that was before my time.

But I was there for the early years of the current DNA typing technology, Short Tandem Repeats (STRs). Those were the days in which we tested mainly blood, semen, and saliva.  We had a good idea of what we could and couldn’t get results from and we ended up with a lot of single-source DNA profiles.  These result in straight forward comparisons to reference samples which yield either an exclusion, if the profiles don’t match, or a match.  In the case of a match, we calculate and issue some crazy-big statistic that illustrates to the reader (the investigator or attorney or juror) just how significant this match is (spoiler alert: the number is often in the quadrillions – matches are pretty darn significant).  And as great as this is and was, the criminal justice system wanted (and in many cases, needed) more.

Science over time, I’ve found, rarely disappoints.  The techniques and products that result from years of experimentation, trial and error, grant funding and academic research end up being a culmination of the best approach among many.

Instead of changing the sites we used for forensic DNA typing, researchers found that we could extract and clean up the DNA a little better and attain higher sensitivity.  They modified the primers and added a few more.  They improved the reagents that we used to get our profiles and made them a little more robust. They made instruments that could automate sample processing so that we could do more samples in less time.  All of this has led to higher throughput and more sensitive results.

Currently, scientists are not just attempting to get DNA profiles from well-defined body fluid stains, as before, but also from areas of evidence items that have tested faintly positive for a body fluid. They are swabbing areas of items that someone in the case may have touched.  These types of samples have much, much fewer cells than, say, a fat drop of blood.  And, while significant to the case and incident at hand, these samples are likely to contain not only very few cells, but mixtures of more than one person’s DNA, further complicating the analysis.

3. Perhaps DNA was deposited at an adequate level, but much of it was washed away or degraded over time. 

It’s important to remember that DNA is a molecule, one with millions of parts.  Cells must be intact in order to properly preserve the DNA.  And hundreds of cells must be present in a sample in order to obtain a decent profile for comparison. Wiping or washing a surface can remove cells. Environmental factors such as heat, UV light, or bacteria can break cells open, exposing DNA and ultimately breaking it down.

Also, it’s useful to know that the laboratory process, itself, is lengthy, requiring many phases, none of which perfectly preserve all of the DNA in the sample from one step to the next.  If I detect 200 cells in a sample in the lab, it doesn’t mean that 200 cells were originally deposited on the evidence item at the time of the crime.  Even in the best evidence-preservation scenario, there is loss of genetic material on the crime-scene-through-laboratory-testing journey.

In the end, as much as I love forensic DNA (and I hope you do, too), it’s important to keep its limitations in perspective in every case. The presence of DNA evidence does not prove guilt. The absence of DNA evidence does not prove innocence. The current state of forensic DNA technology is, however, amazing! I think we can all relish in that without abandoning our role as critical thinkers.


Megan Inslee spent 13 years as a DNA forensic scientist in Washington State.  She has her Bachelor’s in Biology as well as her Master’s in the Genetics track of Laboratory Medicine from the University of Washington. She currently resides on an island outside of Seattle with her husband and three small children, writing technical documents, preparing grant proposals, and providing consultation on a freelance basis.


Posted by on March 29, 2016 in DNA, Guest Blogger, Uncategorized

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