Courtroom Knife Wound Analysis Presents Challenges

by Andrea Campbell

In Urbana, Ohio, about 40 miles northwest of Columbus, a grisly murder took place in a rented duplex. Some dismembered remains of Jessica Rae Sacco were found in the shower. Gary Zerkle, the landlord, had been approached by Sacco’s mother who came looking for her 21-year old daughter after not hearing for too long. 

Zerkle took the key and went to check it out himself and once inside, encountered a locked bathroom door.

Jessica Rae Sacco

"I didn't think that was right," he said of the locked bathroom door. "Sometimes you get a gut feeling."

Reports say he removed the doorknob and pried open the door. It was the look behind the shower curtain that he wasn’t prepared for. "I pulled it back, and that was it," he said. "And I zoomed out the front door... I was trying to gasp for air."

Backstory

Police say that Sacco had moved to Urbana from California the year before. The duplex she shared with her on-again, off-again boyfriend Matthew Puccio rented for $360 a month. In the latter part of the year, Andrew and Kandis Forney, of Fenton, Michigan, began staying with them.

Allegedly, Puccio had killed Jessica Rae Sacco by placing a bag over her head and suffocating her. The Forneys and yet another couple, Christopher Wright and Sharon Cook, of Urbana, are accused of helping with her dismemberment. Reports from police say that some of her body parts were found miles away in Kentucky.

According to an article for the Huffington Post about the intent, “Police would not discuss a motive for the killing, which they believe occurred around March 22. Police allege the Forneys, Wright and Cook were in the apartment when Sacco was killed but failed to intervene. Police say Puccio and Andrew Forney moved Sacco's body to the bathtub and dismembered it.”

Left to right: Matthew Starr Puccio, 25
Andrew Peter Forney, 26 (helped with dismemberment)
Kandis Jenniene Forney, 25 (helped cover up) Christopher Wright, 37 (cover up)
Sharon Cook, 25 (cover up)

Follow-up form the police chief said that Sacco, took classes at a local college and had only been in Urbana about a year after she moved there from California. He said Puccio had only been in Urbana a few months. Both were unemployed.

While the evidence in this case has multiple witnesses and overwhelming physical clues because of the dismemberment, typically the science used to identify knife and saw mark wounds, and the examination and its interpretation in bone has received little more than a cursory consideration in the forensic science industry.

History of Saw Mark Analysis

In the 1970s two science researchers attempted to introduce the topic of saw marks and toolmark analysis in bone to make it more useful to the field of forensic science. Wolfgang Bonte was one of the first who made a concentrated effort to more closely examine and describe saw mark striae in human bone. His casework however suffered limitations in that he failed to understand and recognize saw cutting action. 

In 1978, another scientist, R.O.Andahl attempted to describe saw cut characteristics in metal and animal bone, but his work in medicolegal cases of human dismemberment pointed up the need to analyze these characteristics more fully as his examples were often too simple and less than accurate. There needed to be an improvement in understanding not only the different areas of toolmark characteristics but to have a standardized way to describe forensically the principles of tool action in a cut.

Present Case Studies

The problem with today’s analysis is that there are many differences between knife cut wounds and saw mark analyses on cut bone. The ability to accurately describe in a court of law the features involving dimensions, the elements depicting wounds, and how to discriminate between different classes of saws and knives is still a tricky element. There is no standardization, meaning, it does not have “forensic standing” as a element of crime—it cannot pass Daubert evidentiary standards—and therefore testimony in that regard is just one person’s opinion. Steven A. Symes, Ph.D is the first researcher to publish a doctoral dissertation on the topic of saw mark analyses of cut bone, completed in 1992. He worked on and aided over 200 dismemberment cases involving approximately 700 to 10000 knife cut wound cases. Symes sees the diagnostic potential of developing a methodology to describe the features of cut wounds but it has yet to be implemented fully.

Problematic Terminology

Symes believes that since knife wounds are second only to ballistic injuries as the major cause of violent death in America, the widespread use of meaningless and misleading descriptors such as "sharp", "single-edged blade" and “hesitation mark" (which erroneously implies behavior) are common and may result in serious misinterpretation by attorneys, judges and juries.

The sharp force trauma that appears as an incised wound can be completed with any tool that has a sharp edge. Most of the incised wounds are created by some class of knife and are recognized as sharp force trauma. Most wounds are commonly termed a “knife stab wound” (KSW). But the term KSW is often misused, particularly by anthropologists, since most wounds they examine are without soft tissue.

Incised knife cut wounds are often described as wounds to the bone but are not necessarily due to stabbing. A KCW in bone is indicated when a sharp edged tool superficially incises bone while traversing over the surface of the bone. Symes thinks that forensic students are taught stereotypical adages when it comes to terminology. The difficulties with testimony fall on the fact that, “anthropologists and pathologists conduct numerous saw and knife mark analyses on dry and fresh bone, most professionals are reluctant to examine this bone within the soft tissue." In an article entitled Knife and Saw Toolmark Analysis in Bone, “the reasons for this avoidance include, but are perhaps not limited to: 1) difficulties in examining and transporting decomposed tissues, 2) a lack of equipment or training to process the remains after soft tissue examination, and 3) a general avoidance, 4) a lack of interest in the soft tissues in general, or finally 5) it’s just too damn difficult. Unfortunately, the situation often applies to forensic anthropologists and occasionally to medical examiners and coroners.”

So while the Sacco case might not hinge on knife wound analysis and toolmark evidence, this area of forensic science needs to be further examined and documented for standardized testing and ultimately, courtroom testimony.

Resources:

Steven A. Symes, Ph.D. and Erin N. Chapman, M.S., et al. Knife and Saw Toolmark Analysis in Bone: A Manual Designed for theExamination of Criminal Mutilation and Dismemberment, December 2010

Rodriguez, Barbara. JessicaRae Sacco, Dismemberment: 5 Suspects Arrested In Horrific Ohio Slaying, April, 2, 2012

Taphonomy – Edged, Incised, Hacking, and Impaling Traumas(Caution, photographs may be disturbing) 

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The 'Smart' Bullet is on the Horizon

by Andrea Campbell

Look Up in the Sky!

New technology is a slow and steady march no matter who develops it. I am always torn when a new weapon is developed, and the subject of today’s spotlight is no less frightening and anxiety-driven for me because of its dichotomy of being both useful and deadly. We’re talking about a bullet for machine guns—currently—that guides itself to a target more than a mile away, with accuracy to within eight inches.

The Stuff of Movies

This missile-like bullet was the stuff of fiction such as with the futuristic movie Runaway, a 1984 film written by Michael Crichton, a writer who had an uncanny ability to see what’s coming down the pike. The missile of today, however, can really twist and turn its way around objects, making up to 30 corrections per second.

Can You Imagine?

Developed for the military or law enforcement by Sandia labs, Red Jones, one of the researchers who worked on the laser-guided bullet says, “Where we’re headed, we’re going to be limited only by our imagination.”

Throughout history under the auspices of the U.S. Department of Defense, tens of millions of contract dollars went to companies for just such a weapon. Previously, engineers discovered that the M2, a belt-fed machine gun and standard issue in the U.S. Army 80 years ago, when fired at a distance of 1,000 meters—more than half a mile—would often miss the target by as much as roughly 10 meters.

Small but Smart

Only three years in the making, the prototype bullet is amazingly small—only four inches long and, at an inch-and-a-half in diameter, is a 50 caliber bullet. It operates using an optical sensor, which seeks and stays with a laser beam focused on a target. It also creates outputs from the optical sensors in order to steer the projectile to the target.

“The sensor,” according to Sandia labs, “sends information to guidance and control electronics that use an algorithm in an 8-bit central processing unit to command electromagnetic actuators. The actuators steer the fins that guide the bullet.” This would be similar to a miniaturized guidance system, normally utilized by actual missiles.

Adam Firestone, an army veteran, claims that: “All of a sudden now you’ve got a way to eliminate the collateral damage issue.”

Will we see a form of these miniature “smart bullets” on the streets for criminal purposes? It’s highly likely but only initially used by the upper most, financially-able suspects like drug runners or pirates. Of course now there are still engineering problems Red Jones explains, that will need to be overcome and certain practical considerations such as: can it be tossed or fall off the back of a truck and still function?

Sandia is looking for investors but from all accounts, expect to see this in an action movie in the near future, and heaven forbid, in the far horizon, hear about it in a criminal justice context.

As seen on the Sandia website: Various licensing and partnering options are available. Please contact the Intellectual Property Department to discuss.

For more information, you can download this PDF from Sandia

Photo images: Sandia labs

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Developing Fingerprints on Submerged Weapons Now a Reality

by Andrea Campbell

When new technology comes down the pike, to me, it’s just as interesting as how it came to be—or whose brainchild it is—as is what the science enables us to do. That’s why when I read about this technique for pulling latent fingerprints off of handguns that have been underwater, I had to share it with you as it is on the cusp of becoming mainstream. Some information about the authors and the tests follow.

Principals

Kathryn Book for nine years has been a Physical Scientist/Forensic Examiner in the Latent Print Operations Unit at the FBI Laboratory in Quantico. Part of her job is to work with the Bureau’s Evidence Response Team providing latent and human remains processing. The other author and teammate of this plan is James Tullbane, a Supervisory Special Agent on the Technical Dive Team in the Evidence Response Team Unit. Previously he worked as a member of the Underwater Search and Evidence Response Team (USERT) for five years. It’s not surprising that this kind of talent has endeavored to take on a discipline as yet unproven.

The Typical Past

Divers who have recovered materials from water in the capacity of providing evidence for collection, detection, preservation and processing of weapons underwater have basically turned the materials over to the Firearms and Toolmarks Units in order to discover any distinguishing characteristics such as caliber, ammunition and other related tasks. Never had the evidence gone first to the laboratory for latent print processing as it was thought that nothing of significance could be collected in the way of individualistic fingerprints.

Book and Tullbane, however, launched some tests and subsequent studies to see if the possibility of latent print detection and recovery of print evidence could be obtained on handguns that had been submerged in water.

Collection Techniques

The current protocol for collecting handguns within the FBI parameters are to: 1. Photograph the weapon in place, 2. Package the evidence in the found water, and, 3. Submit it to firearms for ballistics testing.

The study and new methodology the authors of these tests took upon themselves found great success: latent prints were developed on weapons tossed into various types of water, well up to 70 days under submersion!

What Are Latents?

In order for fingerprints to be deposited on a surface, they are of two types: Eccrine or Sebaceous. Eccrine (or merocrine gland substances) are the major sweat glands of the human body found in virtually all skin and are fingerprints and is made up of sweat or perspiration that is exuded from the pores of our skin and which highlights the friction ridge patterns on our fingertips. These glands produce a clear, odorless substance consisting primarily of water and NaCl, secretions of the apocrine glands. NaCl is mostly reabsorbed in the duct to reduce salt loss.

Sebaceous prints on the other hand, include fatty acids, lipids, cholesterol and glycerides, including both eccrine secretions and the sebum produced by the sebaceous glands; this is an oily secretion comprised of free fatty acids, wax esters, squalene and more. The most likely method of deposit is when someone touches their nose, hair, skin or other object that contains oils. Now the likelihood of developing the water-based or Eccrine prints is unlikely as they will dissipate in water. Sebaceous prints are less soluable—capable of being dissolved—and the potential for reading them after they have been deposited on a weapon thrown into water is greater.

Difficulty in Processing

Several factors make it difficult to pull prints such as, the surface of the weapon in the way of textured surfaces or a phosphate finish on the weapon, previous oiling or storage of the handgun, and a wiping clean of the gun often provide effective in removing all trace of latents.

Test Set-up

For the testing several natural prints were applied to the weapons along with another print using Lightning Powder’s Latent Print Reference Pad, and all were marked and placed on both sides of the barrel and photographed for reference. Although the tests were conducted in a lab in a controlled environment (e.g. plastic containers), the water used was both fresh and salted with Instant Ocean. Nine trials were done using elapsed time intervals up to 70 days.

Results

Regardless of method of development, processing handguns immediately after removal from water yielded positive results. There were some factors that help to determine the ideal conditions and the things that affect less than prime results are: handguns should be processed immediately, the water temperature if too warm impacts the results; the best results occurred with metal weapons in cold water; and the addition of heat and salt greatly reduces the detection of latent prints.

Obviously further testing and documentation is needed for presentation in court, and evidence proofs in court, but we are very encouraged this will become a mainstay for processing fingerprints from guns thrown into water.

Sources

--Book, Mary Kathryn and James Tullbane. "Detection of latent prints on handguns after submersion in water" Adapted from Evidence Technology Magazine, September-October 2011, pages 22-25 and 29.

Image: Stuart Miles / FreeDigitalPhotos.net

Gun on dock: Image: Simon Howden / FreeDigitalPhotos.net

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Dying in Water: Clues for Foul Play

"They could be drowning."

by Andrea Campbell

I don’t know if you have ever had the conversation with someone about the worst way to die? Even though I am a swimmer, drowning and the panic associated with taking in water and then succumbing to drowning has been a fear of mine.

That’s why when I was reading about water-related death investigation, I became fascinated about this particular area of examination. Obviously the most common way of drowning would be in a submerged vehicle—a tactic Susan Smith used to kill her small children—then there is drowning in a pool, bath, hot tub or a river, and, yes, even a bucket.

A death investigator looks for certain sign posts that alert him to the possibility of foul play. While we talk about some of the clues the water investigator looks for, you will notice that many of the red-flag indicators are based on well-thought-out common sense ideas and principles. Investigator Kevin L. Erskine—who developed a Master Course in Water-Related Death for the Ohio Peace Officer’s Training Academy and a Children’s Ice Drowning Prevention Workshop—has the wherewithal and savvy to demonstrate just how interesting his discipline is. He has also remarked that if you recognize more than one of the potential indicators of foul play, it gives you the determination to look further than just accepting it as an “accidental” mishap.

Bath Tub or Hot Tub Drowning

Parents have been known to dunk their children as punishment and word from expert's has it, it’s widely practiced. On a child’s body, certainly signs of injury—fingerprint grip marks, or bruising on both sides of the neck could indicate a form of strangulation, while, other bruises showing up around the neck or behind the ears can indicate the assault of forced dunking.

Teerapun FreeDigitalPhotos.net

Other clues would be: the fact that parent’s or caretaker’s clothes are dry; water samples that contain vomit, mucus, soap or urine; inconsistent water temperature, meaning, too hot may be punishment by scalding, or, if the water tests cold or if the water has been mopped up—or wet towels are around—the perpetrator may have waited too long to call or tried to hide a water fight or struggle. Look too, for things missing: no toys, washcloths or soap? These items will usually support an actual claim of bathing.

Also, if during an interview, the parent claims he was distracted yet a sound barrier prevents anyone from hearing the doorbell, an investigator may have reason to look deeper than first believed. Of course, with an elderly person’s drowning, look for a new life insurance policy, severe or terminal illness or disease of the victim, or prior domestic-violence reports.

Submerged Vehicles

If you’ve been watching any fictional mysteries or detective shows lately, you will come across the body in the car scenario where the driver’s seat has been readjusted and couldn’t possibly fit the 5-foot tall victim. Erskine says too, to look at the vehicle’s gearshift—was it in neutral or drive? Is there anything weighing down the accelerator? There is a long checklist of clues to look for, but if there is a blow to the victim’s head and the car or truck is relatively undamaged, that may point to suspicious circumstances for sure.

As you are beginning to see, this can be a lengthy, interesting concept. For more than just casual reading, you might want to check out Erskine’s book with Erica J. Armstrong: Water-Related Death Investigation:Practical Methods and Forensic Applications, published by CRC Press.  http://www.crcpress.com

Source: Evidence Technology Magazine, May-June 2011.  http://www.evidencemagazine.com

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Junk Science Defined

by Andrea Campbell

I often talk to readers about their frustration over conflicting information which is thrust at them under the guise of being “scientific.” For example, a few years ago there were published studies about eggs as related to a healthy diet—were they a cholesterol risk? and should they should be restricted? Today, we read articles touting eggs as an excellent source of protein and are told the benefits outweigh any supposed cholesterol risk assessment or trial. This same type of controversy has been applied to many foodstuffs, vitamin supplements, drugs and even forensic science. Aspirin in, aspirin out; dairy in, dairy out, evidence in, evidence out. What is a reader to believe?

I remember an article published in Imprimis by Lee Ann Fisher Baron, who was at that time, Savona Professor for Natural Sciences at Hillsdale College. Her writing zeroed in on some of that frustration and provides suggestions. Baron believes there has been much political abuse of scientific research. She says, “From persistent doomsday scenarios like global warming to the latest ergonomic arguments for near-total regulation of the American workplace, this abuse of science represents not only an economic threat, but a threat to freedom as well.” To further define what she means by “threat,” Baron sites Americans inability to distinguish solid science from “junk science.”

Further, Baron argues that science has the ability to change history. As fruit of this, she points to the discovery of antibiotics, polymers, and the importance of the Human Genome Project as key discoveries in both the past and future of our lives. In addition to the benefits though, we must also look at apparent drawbacks: that is, in order to come up with these revolutionary discoveries, science is also prone to error, and publishes findings that are just plain wrong or wrong-headed in their thinking. The proper scientific approach to projects should involve the “scientific method.” This type of methodology is based on a precise set of steps or experiments that can be repeated with the same results by anyone.

One of the best arbiters of testing success then is the use of “the control.” We’ll explain control using a hypothetical—let’s say that there is a vaccine that can lengthen the interval between blood sugar levels for a diabetic, in order to prevent severe highs or lows. Two or more groups should be formed to assure the accuracy of the tests. The larger group should be divided into a group of subjects who take the actual vaccine, and a second group is given a placebo.

To further validate the test, neither group should be told which medication they are taking. And to complete the facilitation of true scientific testing, the researchers who administer the vaccine should not know which group is which, thereby creating a “double-blind.” By working under these secret test arrangements, the researchers can measure the “placebo effect”—a phenomenon whereby patients improve because they falsely believe they are receiving medicine. Also, with the researchers in the dark as to who is getting what, it completes the exam by precluding any prejudice they may unknowingly present in their reports.

In an ideal world, a scientist will publish his results, present his paper, and allow the research community to evaluate his findings, sometimes called “peer review.” Others will review the articles, repeat any relevant tests, and question the various conclusions. Junk science, Baron claims, bypasses this process and is often presented to the public under the aegis of “expert” status and whole cloth truth.

So what is a reader to do to protect themselves against the onslaught of guesstimation? Baron suggests that schools up their curricula and imbue students with a love of research. Teach them to become pit-bulls for accuracy. Stimulate their minds with valuable, educational experiments—not like a Seattle middle school, which taught children the eating habits of birds by trying to pick up Cheerios with tongue depressors, toothpicks, spoons and clothespins between their teeth!

In general, Baron suggests: we should be careful to only accept evidence after it has been subjected to the scientific method; that we read everything with a healthy skepticism, and ask questions instead of blindly believing what we hear or read.

Photos and graphics: Clipart.com

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Tattoos Are Us

by Andrea Campbell

We have talked about tattoos and distinctive identification marks before. Just recently, my friend, colleague and author, Dr. Doug Lyle, sent out a blog note that touched on the subject of tattoos. He tells us about Anthony Garcia. Anthony (pictured above) supposedly belongs to the Rivera-13 gang in Pico Rivera, California. He allegedly shot and killed 23-year-old John Juarez in a liquor store four years ago. And he almost got away with it. Almost. Lyle says, “LA County Sheriff’s Department homicide investigator Kevin Lloyd was flipping through a collect of gang member tattoos when he stumbled on Garcia’s image. Imagine his shock when he saw that Garcia had a detailed tattoo of the crime scene splashed across his chest under the banner ‘Rivera Kills.’ It’ll be interesting to see how they use this is court but one thing I know for sure—if you put this in a book, no one would believe it.”

Another Ink Trail 

The FBI site recounts a story about a Los Angeles patrol officer who stopped a vehicle for a traffic violation. While checking the plates, they discovered that the vehicle had been stolen and arrest the driver, Richard Coleman. Of course, police book Coleman and in the process, police write out a description of the man and take photographs of his tattoos for the booking record.

Then about three weeks later, investigators are working on a home invasion case of an elderly couple in Denver, and the victims describe a male wearing a ski mask who broke into their home and beat and robbed them. Through the course of the interview, the victims describe a tattoo of a spider the robber had on his right hand, and the name, “Goldie” in ink across the back of his neck. The Denver police then make a search using N-DEx and pump in the only information they have, including the sex of the perpetrator and the location and descriptions of his tattoos. The search turns up a tattoo match with the Los Angeles booking report, including the criminal history of—you guessed it, Richard Coleman.

 N-DEx

An FBI diagram is shown about how N-DEx works, and when this program is fully deployed it will be able to do:

• Nationwide searches from a single access point;
•  Searches by “modus operandi” and for clothing, tattoos, associates, cars, etc.—linking individuals, places, and things; 
• Notifications of similar investigations and suspects; 
• Identification of criminal activity hotspots and crime trends;
• Threat level assessments of individuals and addresses; and 
• Visualization and mapping features

Telling Artifacts

Of course, many military men and those convicted and doing a stretch in prison often ink their experience on their person. We’ve also seen individuals who declare their hatred of others in bold ink somewhere on their body. One of the more famous haters is Charles Mansion who has a swastika tattoo on his forehead (and it’s not even very good ink).

Not Popular with Jurors 

Joe Navarro, ex-FBI agent and author who we’ve had on Women in Crime Ink blog before, says that he has been involved in many occasions where jurors were questioned about the appearance of tattoos—and, in multiple inquiries and with multiple groups of people—that jurors think of tattoos as “… being ‘low status’ (low class) adornments and/ vestiges of youthful indiscretion, which, in general, were not very well liked.” 

Photo Images:

• Photos of gang tattoos (fingers, mouth)   

• Diagram of N-DEx logo and search  

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Ways to Die: Hanging

by Andrea Campbell

I am pretty sure it's not often that you sit around and imagine what it's like to die by hanging, gunshot wounds, drowning, and all the other means to expire. But mystery writers and novelists have to consider these things for their own fictional world. So, who do you turn to for information? 

Well, a lot of Mystery Writers of America members look to Doug Lyle, MD for answers. You remember D.P. Lyle when we featured his book, Stress Fracture on Women In Crime Ink not too long ago? Today, we welcome him back as a guest editor to answer a question he received on his own blog, The Writer's Forensics Blog, and this particular query is about hanging. Here's Doug's answer to this question:

Question: What Happens When Someone Is Hanged?

Q.: I’ve got a couple of questions about hanging. I have a 140-pound man of slight build who has been hanged. His neck is not broken and thus he is strangling. His hands are bound. How long might he survive before death? Would he lose consciousness well before or shortly before death? If he is taken down before death, we would certainly see abrasion of the neck. What else would we see? If unconscious, would he revive quickly? Could his injuries be life-threatening? (I’m thinking of throat swelling here) I am looking at pre-modern society here. No ER or modern medicine. 

Doug Lyle: In hangings, death results from asphyxia, which is the reduction of oxygen to the brain. Asphyxia in hangings results from the compression of the airways and the carotid arteries (the arteries on either side of the neck that carry blood to the brain) by a noose or other ligature that is pulled tight by the body weight. Thus, the victim must be completely or partially suspended.

Though the airway can be compressed and breathing can be interrupted, the real cause of loss of consciousness and death in most hangings is compression of the carotid arteries, which blocks blood flow to the brain. 

Except for judicial (legally directed) hangings, fractures of the cervical vertebrae (spinal bones of the neck) are uncommon. The reason is that these fractures require that the body drop a sufficient distance to break them. How far is this? The answer depends upon several factors. Individuals who are obese, have small neck musculature, or who have arthritis of the cervical spine may suffer neck fractures quite easily. Just the opposite is true for muscular, thick-necked persons. In judicial hangings, these factors are considered in gauging the distance of the drop. Too little drop and the condemned person is strangled to death, too far and he could be decapitated.

The neck markings seen after hanging depends mainly on the nature of the noose used. Soft nooses such as sheets may leave little or no markings. Bruises and abrasions are not common with softer devices. In fact, if the victim uses a soft noose and if the body is discovered fairly quickly and cut down, the ME may not be able to find any marks at all. A rope or cord may leave a very deep, distinct furrow in the victim’s neck. The longer the body hangs, the deeper the furrow. Abrasions and contusions are more common with these types of nooses. Occasionally the furrow and any associated bruising may reveal the braid pattern of a rope or the link configuration of a chain.

In hangings, the furrow and the bruising will follow a typical course. The pattern is that of an inverted V. The furrow tends to be diagonal across the neck with its high end where the knot is located. The knot is usually to one side. This means that if the knot is to the victim’s left side, the furrow will be lower on the neck and much deeper on the right side and will angle upward toward the left ear. Near the knot, the furrow may shallow and disappear. This pattern is due to the body hanging by the “bottom” of the nose.

Okay, enough about hangings, let’s get to your situation. Since the asphyxia is due to compression of the arteries and not the prevention of breathing, loss of consciousness occurs very quickly, usually in a minute or less and maybe as short as 20 seconds. The brain needs a continuous supply of blood and when this is interrupted, consciousness is lost quickly. Death may take from one to five or six minutes.

If your victim is found within two to three minutes, he would be unconscious but could wake up fairly quickly—in a couple of minutes. Or not. Some people die in a minute while others can take many minutes. Go with a couple of minutes but not longer and you’ll be okay. He would probably have the typical V-shaped bruises on his neck and a furrow that would resolve over a half hour or so.

He could return completely to normal or be left with brain damage or even remain in a coma for hours, days, weeks, months, years, or forever. It all depends upon how long the brain was deprived of blood and luck. This varies from person to person.

D.P. Lyle, MD

Website: http://www.dplylemd.com

Blog: http://writersforensicsblog.wordpress.com

Coming June 2011: HOT LIGHTS, COLD STEEL, a Dub Walker Thriller

Image Credits:

http://commons.wikimedia.org/wiki/File:Hanging.gif

Author's clipart.com account

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DNA Manipulation

by Andrea Campbell

When technology gets better, there will always be someone who wants to defeat the system. It’s comforting to know that progress is continually being made in order to stay ahead of the criminals.

We’ve talked a lot about biometrics and DNA. These are thought of as irrefutable biological characteristics that help to define and identify just who we are. That’s why when I saw the headline, “DNA Paternity Test Almost Fooled,” I had to know more.

Who’s Your Daddy?

Paternity tests use DNA to allow people to discover their origins, such as who are my mother and father? DNA has longed been used for this process and there are reasons that someone would not want to be found—mainly child support payments. In 2007, someone found a way to confuse the identification system temporarily and it has now prompted a new methodology because of this person’s brash moves.

Apparently the fraud attempt was predicated by a DNA paternity test.

The paternity test is done just as one would do for a crime suspect—samples of saliva cells are collected from the mouth. In this particular case, Dr. José Antonio Lorente Acosta, Director of the Laboratory of Genetic Identification at the University of Granada, carries out forensic tests just like these as commissioned by the court in cases of paternity, and for the identification of possible criminals, or else to contribute to DNA databases such as in the case of trying to locate missing relatives.

In this 2007 case, epithelial cells were collected from the interior of the mouth by a person undergoing a paternity test, which gave an incongruous result. The research team questioned their procedure and found they had not changed anything. The suspect washed his mouth and, “... after repeating the analysis, there was only one possible conclusion: In the mouth of that man there was DNA from two different persons,” says Dr. Acosta. They, of course, arranged to meet the subject again and found out that shortly before he took the test, he mixed his saliva with someone else’s that he had concealed on his person in a small container, hoping to mislead detectives. As it turns out, the test was repeated and he was found to be the biological father in that particular case of judicial investigation. This case prompted a modification of all future tests, as now it would be compulsory for the donor to wash his mouth out, but this time in the presence of a witness.

The Grim Sleeper Case

A Los Angeles' serial killer who was thought to have killed at least 10 people, was caught by detectives who used a familial DNA search and that, and new databases, has made somewhat of a breakthrough. Only Colorado and California currently have laws specifically allowing the use of familial DNA match. The practice has drawn criticism from privacy advocates who fear that innocent family members will be targeted if they have the misfortune of being related to a criminal.

The research policy, however, is restricted to major violent crimes, and only after all other investigative methods have failed. Apparently the majority of the Grim Sleeper’s killings were committed in the 1980s. Unfortunately the crimes restarted after a 13-year absence, with the latest one occurring in 2007. This prompted Los Angeles' police to look for a “similar” DNA profile. Hoping they might find a relative for leads, after running several tests, some DNA was identified as the suspect’s son. The after-effects of this case and use of familial DNA will surely set precedents for its future use, as well as new policies as other states adopt the process. First published in Forensic Magazine.

Take That Robbers: DNA Mist

This new technology is fairly genius and was discovered in the Netherlands. We’ve all seen in films where the bank puts explosive dye packs in the money bag in order to mark the criminal after it explodes. They open the bag to get the money and are showered with indelible ink. Now there is a DNA spray mist! The applicator is positioned on the door of a bank or other business that has funds. Every person who enters is misted with a DNA spray that has no odor and is completely unnoticeable. The synthetic DNA compound settles onto hair, clothing and skin without knowledge. Of course, somewhere on this person is a trail that has a fluorescent marker that can be detected using ultraviolet light. Not only that, but the DNA can be made unique to a particular location. Good thinking that.

All photos are Clipart.com

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What’s in a Face? Biometrics and Facial Identification

by Andrea Campbell 

We've all seen facial biometrics in the movies where a security camera picks out a terrorist subject or supposed perpetrator, reads their face and maps out a facial recognition identifier for law enforcement. It’s really flashy, cool and fast. Does it work that way? Well, yes and no. Let’s start at the beginning. 

Security and Biometrics

In the past, security measures have used a card, a token or key to get into closed doors. Other methods involve a password, code or something you must type in, like a series of numbers. The goal for biometrics is heightened security; meaning, it involves the identity of an actual person to gain entry. The word biometrics means it is some physical characteristic, or personal trait used to trigger an automatic recognition. We already use biometrics with fingerprints, a written signature, voice recognition or a retinal scan. Other lesser-used body differentials are someone’s gait, their ears, hand or finger geometry, or even their odor.


Several Keys

The key to biometrics' usefulness is that the characteristic must be measurable, and once presented to a sensor, can be converted into a quantifiable digital format. It is only good if it can be automated down to a number of seconds for retrieval. A system is called robust, if it can read traits that are subject to change. For example, the iris of the eye won’t change significantly over time, and it is more robust than someone’s voice. Plus, the more distinctive the identifier is, the better. A retinal scan would be more distinctive than hand or finger geometry.

Biometrics needs to perform two functions: identify and verify. In order to satisfy an identification it must work against records in a database, which it can search through for results, such as mugshots that are used by police. This comparison is called a "one to many" search and presents a best match result. Verification, on the other hand, is a system that relies on input from the user, generally via the password or another form of identity. This would be a "one to one" search, such as would be done with a computer allowing someone access using a private code. 

Did You Know? 


The police in Tampa Bay, Florida, used Indentix’s facial recognition software to screen at Super Bowl XXXV in January 2001. The search was for potential terrorists and criminals in attendance. The results? The system found 19 people with pending arrest warrants. Facial recognition is often able to operate with the used of surveillance cameras or closed circuit television (CCTV).

(Photo Courtesy of the Federal Bureau of Investigation) 

How Does It Work?

Facial recognition can be used to locate criminals, terrorists or missing children by using a five-step methodology. First, the image must be captured. This can be accomplished by scanning a photograph or using a camera to acquire a live picture of a subject. Fast moving video can also be turned into still shots. Next the software program seeks to detect the location of any faces in the acquired image, and it looks for two eyes and a mouth set into an oval shape. Once a face has been targeted, it is analyzed using spatial geometry. There are different methods available depending on the software, but this it is commonly referred to as the eigenface method. The system has templates that generate unique features for comparisons. That is to say, algorithms identify faces by extracting the landmarks of someone’s face and using the relative position, size and shape of eyes, nose, cheekbones and jaw. In other words, it measures the distance between the eyes, the depth of eye sockets, the shape of cheekbones, etc., but it actually ignores facial hair or hairstyles. These are then compared to a database of known faces, and finally, the scores are looked at by the end user for a determination. 

Better Than People


The software algorithms are generally better than people estimations. People are very good at recognizing people they know from surveillance film. With unfamiliar faces, however, not so good. The reasons for this are believed to be that people just aren’t good at it and they have a short attention span. To test this point, a British study used trained supermarket cashiers to screen shoppers. The shoppers were of four types. One had a shopping card with a recent photo, another had a card with modifications to their photo such as a minor hairstyle change or the addition of glasses. A third shopper’s card was issued that was actually of a different person who resembled them somewhat, and, finally, a shopper was issued a card where the only similar characteristic was the same sex and race as the shopper.

When the various cards were presented to the checkout clerks, more than half of the fraudulent cards were accepted. The breakdown was as follows. 34 percent of the cards that did not look like the shopper were accepted, 14 percent of the cards where the appearance had been altered were accepted, and 7 percent of the unchanged cards were rejected by the clerks. Time plays a factor too, as a human being's ability to detect critical signals drops rapidly after the start of a task, so that within 35 minutes their focus to task drops significantly. 

Current Uses 


A London borough uses a CCTV system, German Federal Police use it at a fully automated border station at an airport, Australia also has a system called SmartGate, and casinos and United States law enforcement agencies employ systems. It’s also been used at highly publicized trials, and to ensure fair counts for elections in Mexico.

The IAFIS (Integrated Automated Fingerprint Identification System) has an Interstate Photo File of 9,695,672 photos for over 5,629,772 records. The U.S. Department of State operates one of the largest face recognition systems in the world with more than 75 million photographs, and it is actively used for visa processing.

Results Are Weaker


The results of biometric facial recognition are still weaker and less efficient than the other methods, but police like it because it doesn’t require aid or consent from the test subject, and it can be installed in public places. 

Faces Are Public 


How do you feel about having your image captured, however? There is some controversy, but the privacy issue raised here is not protected by the U.S. Constitution. Under current law, the type of facial recognition used by law enforcement to monitor public places is legal because according to the United States Supreme Court, a person does not have a reasonable expectation of privacy because the physical characteristics used, such as one’s facial characteristics, voice, and handwriting, are constantly exposed to the public. 

New Technology 

A newly emerging trend, claimed to achieve previously unseen accuracies, is three-dimensional face recognition. This technique uses 3-D sensors to capture information about the shape of a face. You may also see technology developed as a security measure at ATMs, where a webcam image would be compared to a photo card.

When Madeleine McCann disappeared at Praia de Luz in Portugal, the British police asked visitors at the Ocean Club Resort to provide any photographs they may have taken in an attempt to identify the abductor of the missing child as part of the investigation, as some modern cameras have a focus and measure component.

Hey, even Facebook has a program that identifies faces in photos and allows you to tag other people you may know. I’m just saying, it’s going to be everywhere. 


Other Resource:

Bonsor, Kevin, and Ryan Johnson.  "How Facial Recognition Systems Work"  HowStuffWorks, January 2011.

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