Forensic Friday: The Mystery of DNA

Alec Jeffreys

It has been thirty years since the first use of DNA to aid in a criminal investigation. Over in the U.K. in 1984, Professor Alec Jeffreys and his colleagues developed “genetic fingerprinting” which uses DNA to identify individuals. Two years later DNA evidence determined the identity of a killer in two related cases of rape and murder. Two years after that, a man serving time for a crime he didn’t commit was exonerated through the use of DNA evidence.

Today’s television shows such as CSI, NCIS, and Law and Order use forensics and witty repartee to find their culprit in less than an hour. In reality, law enforcement officers need much more time to solve their cases. At any crime scene, evidence is painstakingly collected. And I do mean painstakingly-tweezers are often a CSI Technician’s tool of choice. The evidence is then processed through the system (identified, inventoried, and logged). But in order for evidence to be of any use, the detectives on the case must have a working theory. Otherwise the items are simply a collection of artifacts.

So what is DNA? Deoxyribonucleic acid is a self-replicating material that carries the genetic instructions used in growth, development, functioning and reproduction of ALL known living organisms. It is the main constituent of chromosomes. The key in forensics is that DNA is unique for every individual.

During an investigation the detectives must have a reasonable theory with regard to their suspect to be able to request a DNA sample. It is not feasible for the police to request samples of any and every person known to the victim. Therefore, clues and leads must be followed to build a case. Many times non-DNA evidence is sufficient to make an arrest. Other times, DNA is the lynchpin to solve the crime. Unfortunately, law enforcement officers must be patient. According to Forensic Scientist Heather Sergeant on Public Agency Training Council, it takes over fifty four hours to correctly process DNA evidence. Certainly quite a bit longer than our TV characters would have us believe.

What is your favorite TV crime show?

Forensic Friday: Unsolved Mysteries

Forensic Friday: Unsolved Mysteries

Jack the Ripper. The Black Dahlia. Bugsy Siegel. Bob Crane. The public is intrigued by unsolved mysteries no matter how long ago they occurred. On the other hand, the police are no doubt frustrated. As time passes, the trail gets colder and colder.

One such case is that of Sir Harry Oakes, an American who later became a British citizen and moved to the Bahamas to avoid paying income taxes on the millions he earned from his gold mine. Born in Sangerville, Maine, Oakes traveled to Alaksa during the Klondike gold rush, then made his way to Ontario where he finally struck iron ore in 1912. Later that same year, another of his mines struck gold. Ultimately, the gold mine was thought to be the second most productive mine in North America. He claims that he paid nearly $18,000 per day in taxes because of his success.

A multi-millionaire by 1921, Harry decided to go on a world cruise. He met his wife Eunice on the

voyage, and they married almost immediately. They went on to have five children, and he became somewhat of a philanthropist. As the years passed, he tired of paying exorbitant taxes, so he became a British citizen and moved to the Bahamas in 1935. He was knighted by King George VI in 1939. Life was good.

Then on July 7, 1943, Sir Harry was murdered.

The prime suspect was his son-in-law, Alfred Fouquereaux de Marigny. De Marigny was a playboy and heartily disliked by most of Bahamian society. He had been seen arguing with Oakes in the recent past and was known to be regularly short on money. An interesting aside is that the Duke of Windsor (then governor of the British colony) ordered the local criminal investigation division to step aside in favor of two American detectives who regularly provided security for the Duke when he was in the U.S.

At the trial, it was determined that the detectives framed de Marigny by claiming to have found a fingerprint at the scene. In reality, the print had been lifted from the cellophane wrapper on a cigarette package the suspect was giving during questioning. The jury acquitted de Marigny in less than two hours, but he was sent packing off the island a few weeks later.

The case was never reopened, nor was Harold Christie, a guest in the house on the night of the murder, ever questioned. The official autopsy lists a blow to the head as the cause of death. However, de Marigny claims a Nassau doctor told him that Oakes had been shot-a story that coincides with the testimony of the two estate guards on duty.

Books have been written, and movies have been produced, which draw their own conclusions. But the case remains unsolved.

Sometimes forensics have advanced since the time of the original crime creating the opportunity to solve cold cases. Will the murder of Sir Harry Oakes be one of those opportunities?

Forensic Friday: Forensic Archaeology

Forensic Friday: Forensic Archaeology

Photo from Smithsonian Institute

The internet is littered with stories of people stumbling over clandestine burial sites. Farmers unearth skeletons when they plow up long fallow land. Home owners discover bodies when they renovate centuries-old houses. Hikers find victims buried deep in the woods. When that happens the police contact Forensic archaeologists for assistance in identifying the victim. 

Forensic archaeology is the application of archaeological digging techniques to crime scenes. A knowledge of osteology (the study of bones) is used to determine age, gender and height of the deceased. The work is performed with great precision so that no damage is done to the skeleton or possible evidence. During the excavation, the archaeologist will record and preserve anything found at each stage and depth of soil.

Photo from Crimemuseum.org

A variety of methods are used to date items found at the site. Carbon dating is one of the methods used to indicate whether the grave is ancient or recent. In addition, a scientist’s understanding of how materials degrade or decompose over time when buried in certain soil can be helpful in dating a site. In recent years, Forensic archaeologists have also be involved in the excavation of mass graves such as those found in Europe since WWII. Their work has been invaluable at bringing closure to families who have grieved for years wondering what happened to their loved one.

Forensic Friday: Bugs!

Forensic Friday: Bugs!

I don’t mind snakes, but I hate bugs. How about you?

However, insects can play an important part in crime solving. The field of forensic entomology goes back almost a millennium. In 13^th century China a book titled “The Washing Away of Wrongs” describes the first known recorded incident where insects were used in a criminal investigation. A farmer was found murdered in a field of an apparent stabbing. The suspects were told to place their sickles on the ground. Only one sickle attracted blow flies to the trace amounts of blood hidden to the naked eye. This led to the confession by the murderer.

Advancements continued. In 166, Italian physician Francesco Redi disproved the theory of spontaneous generation. French physician Louise Francois Etienne Bergeret published a report in 1855 about the life cycle of insects that he used to prove his hypothesis on how and when the victim died.

How does medicolegal forensic entomology work?

·         Technicians collect insect evidence from the corpse and the crime scene. Depending on which insects’ eggs appear, and where they are located on the body, the medical examiner can determine the approximate time of death (also known as post mortem interval or PMI).

·         Because many insects occur only in certain places or are active only in certain seasons or time of day, potential links can be made to times and locations where other events may have occurred. This information can also indicate if a body has been moved.

·         Medical examiners must keep in mind that rain, humidity levels, sun exposure, and air exposure can impact the presence (or not) of insects.

Photo courtesy of www.purdue.edu

A new subfield is entomotoxicology – the analysis of toxins in the insects found on the corpse – helps investigators determine whether drugs were present in a body at the time of death. In addition, new techniques have been developed to more accurately gather evidence at crime scenes.

Who knew bugs could be so important?

Forensic Friday: Botany

As noted in previous blog posts, forensics has numerous specialty areas. One of those specialties is botany. Forensic botany is the application of plant sciences to criminal investigations. Similar to DNA and fingerprinting, plant material (seeds, leaves, flowers, spores, wood, fruits, cells, hairs and glandular hairs) is often unique to certain plant species and ecological areas. This allows a forensic botanist to narrow down the possibilities surrounding the who, where, and when of a crime.

An example of this is the comparison of pollen at a crime scene and on a suspect. Because even common plants have their own unique combination of pollens at different locations, the botanist may be able to link the suspect to a particular crime scene or determine that the victim has been moved from the original crime scene. Another example is the use of botanical evidence to find “clandestine” graves by examining the changes of disturbed soil. Botanists are knowledgeable about the plants that typically invade disturbed surfaces.

The study of trees and roots is also helpful in an investigation, often for determining the elapsed time of death. Growth rings can be counted to provide the timing of an event, and even partial damage to root growth can suggest the period since an interruption occurred.

The first reported trial that used the expert testimony of a botanist was the Lindbergh baby kidnapping case. Dr. Arthur Koehler was an expert on wood anatomy and identification with the United States Forest Service. He studied the ladder used by the kidnapper, and subsequently presented three kinds of information – identification of the wood used, physical marks left by tools on the wood, and comparison of the wood structure. By matching the annual rings on the wood, Koehler was able to show that the attic board in Bruno Hauptman’s home and the ladder rail had once been a single board. This was one of the most incriminating pieces of evidence in the trial that led to Hauptmann’s conviction.

In the eighty years since the Lindberg trial, the value of botanical trace evidence in criminal and civil cases has been used to bring justice to innumerable victims.

Forensic Friday: Human Memory and Eyewitness Testimony

I manage the dining hall at a boarding school that has nearly 400 students. Periodically, we have issues with the kids not taking their soiled dishes to the dish room or other such minor infractions. We have one young man who is a chronic offender, and he tends to sit at the same table for each of his meals. A couple of weeks ago, one of my staff discovered that “his” table had been left particularly messy after lunch. In order to confirm which student was responsible I had her look through the pictorial directory to identify who had been sitting there. She selected this young man.

There was only one problem. He hadn’t been at school that day.

So much for eyewitness testimony.

Dr. Elizabeth Murray, a forensic anthropologist, and an instructor at College of Mount St. Joseph, has  issued two video courses about forensics through The Teaching Company. Here is a paraphrase of what she says about human memory:

·         Memory is not a video recorder, where everything is seen in the mind’s eye objectively and exactly as it happened. A memory is more of an impression of an event.

·         Depending on our past experience, our brains put different things we’ve experienced into different categories for future recall. When an event occurs that fits one of our schema, our brain pulls out all of the bits of that schema to process the new information and the overlap can mix things up a bit.

·         There are two stages of memory: 1) short-term memory involves the information our brain doesn’t process for future recall because it’s seen an unimportant, and 2) long-term or permanent memory where information is seen as important and therefore stored for future recall.

The key to whether or not we remember an event or person depends on how our brain dealt with the relevant information at the time of the event, and there are many variables that affect this processing such as our beliefs, motives, stress, stereotypes, and environmental factors. In addition, studies have shown that some faces are easier to remember than others. Also, some people are simply better with faces than others. You might not be surprised to discover that the amount of time between the event and when it’s recalled affects the way something is remembered.

Currently, the federal standard for eyewitness testimony in court is that if a witness is very sure of his or her testimony, it is admissible in court. If there is any amount of uncertainty, it’s up to the judge to decide whether it’s allowed or not.

However, studies have shown that the degree of certainty of a witness doesn’t necessarily correlate with the reliability of his or her testimony!

Forensic Friday: The Lost are Found

According to the National Institute of Justice website, every year tens of thousands of people in the U.S. disappear under mysterious circumstances. The site also claims that on any given day there are as many as 100,000 active missing person cases on the desks of law enforcement officers. Moreover, there are an estimated 40,000 unclaimed remains on file at Medical Examiner offices or that have been buried before being identified.

In 2005, the realization of these facts was the impetus for the formation of The National Institute of Justice’s National Missing and Unidentified Persons System (NamUs). A free online system that can be searched by medical examiners, coroners, law enforcement officials and the general public from all over the country, NamUs offers three databases: missing persons, unidentified persons, and unclaimed persons.

Thousands of records have been input into the databases, but are of no use unless someone accesses the information. According to a press release issued in 2011 by the Department of Justice, the remains of sixty-two people have been identified through NamUs and returned to their families. Many of the cases were solved because of the opportunity for the public to search the records or to input photos and identifying marks about their relatives.

There are actions the public can take with regard to NamUs – the most obvious being that if you have information about a missing or unidentified person, you should report the information to the local law enforcement agency. Do you personally know law enforcement officials? Make sure they are aware of NamUs. Do you know the family of a missing person? Encourage the family to visit the NamUs website where they can create a case file. Register to be a public user for the missing persons and unidentified persons databases. This will allow you to input new information about cases.

One by one, with the help of NamUs, the lost are found.

Forensic Friday: Pattern Evidence

Tire track impressions leave behind a unique pattern, therefore are classified as pattern evidence. Just like shoe impressions can help narrow down the brand, style and size, tire tracks have the ability to do the same thing. The type of evidence left behind depends upon the type of surface traveled. A tire can leave an impression in loose sand or snow, but will leave an imprint on a hard surface such as concrete.

There are three types of prints: visible – able to be seen by the naked eye and collected by photography; plastic – three-dimensional and collected by making a cast; and latent – prints not visible to the naked eye. In modern times, latent prints are collected through the use of electrostatic lifter dust.

Once impressions or imprints are collected at the crime scene, experts compare the evidence to a suspect’s shoe or vehicle tire to determine if the item is the same one that left the impression. The reason this works is that as shoes and tires are used, their physical features change over time. For example, a tire out of alignment will create a tire that is heavily worn along one edge.

An example of the use of tire impressions as evidence is in the recent case of former Patriots tight end Aaron Hernandez. Four stones wedged in the tread of the rear passenger-side tire on a vehicle rented to Hernandez enabled investigators match it to the tire tracks left at the scene of the crime. A miniscule yet crucial piece of evidence.

Forensic Friday: The Art of Forgery

I recently started reading “The Art of Forgery” by Noah Charney. Part textbook, part true crime, the book is an intriguing look into the dark side of art. According to the author “art has been copied, misattributed and forged since before biblical times.” He also states that “beyond deliberate fraud, there are many noncriminal reasons why a work of art might be misattributed, sometimes to the benefit of the owner.”

So, how is art authenticated?

For years, the industry relied on connoisseurship. Individuals became “connoisseurs” or experts about an artist or artists by seeing and studying his or her works. The experts examined brushstrokes, the application and thickness of paint, and the way artists painted certain recurring themes. This was the widely accept method to determine authenticity and value until the early 20^th century.

According to Charney “copying art has always been the way young artists learned their trade - copying or imitating another artist's style is only a crime if someone tries to pass off the copy as an original.” History is littered with cases of this type.

The first time science was used to convict a forger was in 1932 at the trial of Otto Wacker. A German art dealer, Wacker commissioned and sold forgeries of the paintings of Vincent Van Gogh. At the trial, the prosecutors brought forth two Van Gogh experts to testify. However, a wrench was thrown in the works when the experts could not agree on which, if any, of the pieces were genuine. To make matters worse, one of the experts repeatedly changed his decisions.

Enter Martin de Wild – a Dutch chemist and author of the 1929 book “The Scientific Examination of Pictures.” He tested the oil paint from several of Wacker's Van Goghs. Resin and lead, chemicals that make oil dry faster, were found to be mixed into the paint. Wacker was convicted based on this evidence and sentenced to a year in jail. He appealed the decision, and his sentence was raised to nineteen months. Probably not the result he expected.

Science continues to be used to authenticate art. And art forgers continue to improve their techniques in an effort to beat science at their own game.

Forensic Friday: Who's Got the Goods?

Colonel Mustard did it with a knife in the library. Mrs. Peacock did it in the ballroom with a candlestick. But what if the evidence is contaminated, and the deed cannot be proven? That’s where chain of evidence comes in.

Chain of evidence, also called chain of custody, is the “chronological documentation showing the seizure, custody, control, transfer, analysis, and disposition of physical or electronic evidence.” The key to this process is for the chain to remain unbroken.

In order for evidence to be used in court to convict someone of a crime, it must be handled in a manner that prevents tampering. The handling must establish that the alleged evidence is in fact related to the alleged crime, rather than having, for example, been “planted” to make someone appear guilty. If there are discrepancies in the process, and it cannot be proven who had the item at a particular point in time, then the chain of custody is severed, and the defendant can ask to have the resulting evidence declared inadmissible.

An identifiable person must always have the physical custody of a piece of evidence, and each transaction involving the evidence must be recorded. Typically, a police officer or detective takes charge of a piece of evidence collected at the crime scene and gives it to an evidence clerk for storage in a secure place.

For those of you who watch CSI or any of the other police dramas on television, you may already be familiar with the process of evidence collection. Documentation begins at the crime scene where a technician photographs the item in its place. Then measurements are taken to indicate the exact location of the item at the scene. A common method to do this is for the technician to select a fixed point at the scene (e.g., the south side of the living room) then measure the distance to the evidence from that point.

Television often portrays police work as fast-paced, glamorous, and exciting. I’m sure it can be, but more often than not a criminal has been convicted because of a tiny anomaly brought to light by meticulous attention to some detail related to the case. (Think Sherlock Holmes or Monk.)

Who is your favorite TV detective?

 

 

 

Forensic Friday: What's in a Bullet?



photo courtesy of www.thecrimemuseum.org

You’re familiar with the concept of fingerprinting, but have you ever heard of ballistic fingerprinting? With all of the crime dramas on television, maybe you recognize the term. For those of you who don’t know “ballistic fingerprinting” is using a variety of forensic techniques to match a bullet to the gun with which it was fired. Fingerprinting is based on the principle that all firearms have variations due to marks left by the machining process. Because the variations aren’t completely polished out, they leave impressions on the bullet.

Calvin Goddard, a physician and ex-army officer, is Army Ordnance titled “Forensic Ballistics” in which he described the use of the comparison microscope. However, more than 100 years prior to his article, a killer was brought to justice in England when the markings on a bullet taken from the victim were matched with a bullet mold belonging to the suspect. (Back then you made your own ammunition).

credited with creation of the term. In 1925, he wrote an article for

photo courtesy of www.wikipedia.org

Goddard went on to form Bureau of Forensic Ballistics, an independent criminological laboratory, because few law enforcement agencies had the capabilities of providing this service.

There are three characteristics used during the identification process. The first is the easiest and most apparent. It is referred to as the “gross difference.” For example, a 10 mm bullet could not have been fired from a 9 mm barrel.

The second classification is striation, the fine grooves etched into the bullet from the spirals of the

photo courtesy of www.thehighroad.com

rifling in the barrel. Rifling varies among manufacturers and models. For example, Smith and Wesson use a right hand twist, and Marlin Firearms uses a 16-groove rifling.

Breech markings are the third classification. This refers to the marks on the cartridge case which are often easier to identify than bullets. The concepts here are that the parts of the weapon that produce the marks on the case are less subject to long-term wear, and that bullets are often severely deformed on impact, destroying much of the markings they acquire.

Goddard’s techniques were used to solve many high profile cases including the Sacco and Vanzetti payroll robbery case during which a paymaster and the guard were killed. A century later these techniques are still used, however, many are performed by computers instead of humans.

 

Forensic Friday: Every Contact Leaves a Trace

photo: dfs.Virginia.gov

In my early college days, I aspired to be a medical technologist. Dr. Pinkerton’s Organic Chemistry class, and the thought of spending hours on end squinting into the eye piece of a microscope sent me running across campus to the Psychology department where I happily stayed until I received my bachelor’s degree in Psychology.

Having said that, I find the forensics aspect of crime solving absolutely fascinating. So much so, that I follow forensic anthropologist Dr. Elizabeth Murray on Facebook and own her two Great Courses on forensics. Not to mention several forensic textbooks. After reading them I no longer look at my hair and clothes the same way.

During the investigation of a crime, hair and fiber are collected at varying points throughout the process, but most notably at the scene of the crime and at the autopsy stage. This can be for the purposes of eliminating individuals from police enquiries as well as to help narrow down the list of suspects. These samples are collected through meticulous and painstaking processes, which are carried out by Crime Scene Investigators who themselves are dressed in protective clothing so that their own clothing and hair do not contaminate any evidence which may pre-exist.

The fibers are then taken back to a lab to be analyzed. It is a time consuming job, and doesn’t happen as quickly as shown on television, but has been crucial in solving many high profile cases including the Lindbergh kidnapping in 1936. Science has come a long way since then, but sometimes it is still the simple details of a single fiber that clinches a conviction.

Forensic Friday: What do Mining, Fireflies and CSI have in Common?

Crime scene investigation is predicated on the theory that no crime can be committed without leaving some sort of evidence behind. Even the tiniest trace. That’s where the chemical Luminol comes in. When mixed with an appropriate oxidizing agent, Luminol exhibits a soft, blue glow. This reaction is known as chemiluminescence, and it’s the same phenomenon that makes fireflies glow.

In crime solving situations, the oxidizing agent is the iron found in

hemoglobin (blood). During testing, the room is darkened, and the CSI technician sprays the chemical evenly across the suspected area. If blood is present, whether fresh or dried, the area will glow for about thirty seconds, and the effect can be documented by a long-exposure photograph. The intensity of the glow does not indicate the original amount present, but indicates only the distribution of trace amounts of substance left behind. Most people don’t realize that tiny particles of blood will cling to most surfaces for years.

Other substances do cause Luminol to glow, so additional tests are required for verification of the results. And because the chemical reaction can destroy other evidence, Luminol may be used only after pursuing other investigative options. It is not used as readily as shown on many television programs.

I was surprised to discover the chemical was originally designed in the 1920s for the German copper mining industry to reveal new sources of ore. It was not until 1937 that German forensic scientist Walter Specht made extensive studies of applying Luminol to crime scenes. Further study was done in 1939 in San Francisco that helped convince law enforcement officers of Luminol’s importance as a crime solving tool.

What other industries have contributed to crime solving?

Forensic Friday: Forensics in a Nutshell

“Luckily, I was born with a silver spoon in my mouth. It gives me the time and money to follow my hobby of scientific crime detection.”

So said Frances Glessner Lee (1878-1962), socialite, heiress to the International Harvester fortune, and creator of the Nutshell Studies of Unexplained Death. Although she hoped to pursue law or medicine, Lee was born in the Gilded Age-the wrong era for women to attend college. Instead, she married early (probably an arranged marriage) and had three children. A long separation finally occurred before the couple divorced in 1914.

“Fanny” learned to make miniatures and took to it with a passion. She created an exact replica of the Chicago Symphony-including ninety musicians, their instruments, sheet music, stands, music cases and other intricate details. Then she met her brother’s good friend George Burgess Magrath, a student t Harvard and eventual medical examiner in Boston.

Through her friendship with Magrath she heard about the difficulties in investigating violent deaths. At that point in time, coroners were not required to have medical degrees, and police officers were not trained in collecting crime scene evidence.



Photo: Corinne Botz

After Fanny came into her inheritance, she was determined to do something about the problem. Eventually, she organized week long seminars during which experts lectured on topics such as victim identification, time of death, interrogation techniques, and more. Years past. In 1943, deciding that the training was not enough and convinced that crimes could be solved by detailed analysis of material evidence, Fanny constructed a crime scene diorama. It took her three months to assemble “The Case of the Hanging Farmer.”

Photo: Corinne Botz

Incredibly effective at teaching detection and observation, the diorama was wildly popular. Fanny followed up with nineteen more, and all became a critical component of the seminars. Maryland Chief Medical Examiner and close friend, Erle Stanley Gardner (author of the Perry Mason mysteries) wrote that “A person studying these models can learn more about circumstantial evidence in an hour than he could learn in months of abstract study.” As a result of her work in the advancement of forensic science, she received an honorary appointment as captain in the New Hampshire State Police.

In 1967, the Nutshells were moved from the Harvard Department of Legal Medicine to the Baltimore Medical Examiner’s office where they are on permanent loan. In 1992 the dioramas were restored for $50,000, and are still used at the seminars used to train investigators from around the country.

Who knew a hobby could make such a substantial impact? What are your hobbies?

Forensic Friday: A Bit of History

Until popular television shows like CSI and NCIS hit the airwaves fifteen years ago, I would hazard a guess that most people didn’t give forensics much thought. However, thanks to these TV dramas, the public is now familiar with terms like accelerant, chain of custody, lividity, and toxicology. And unfortunately for many police departments, fans of these shows believe their viewership makes them experts in the topic. (But that’s another whole blog!)

So where did it all start? Has it only been recently that forensics and other associated sciences were used to solve crimes? I wondered that myself and set about to find the answers.

Dr. Elizabeth Murray, Forensic Anthropologist and Professor at Mount St. Joseph University is a

wealth of knowledge! Consider following her on Facebook. Her posts are fascinating and thought-provoking. She was gracious enough to send me a brief history of forensics, so I thought I’d share a few:

• Julius Caesar’s attending physicians used forensics to determine that of the twenty three wounds on the body, only one proved to be fatal. That was in 44 BC!
• In 250 BC Greek physicians determined that pulse rates increase on patients who are lying.
• China published the first textbook of forensic medicine in 1247.
• Two hundred years later, teeth were used to identify the remains of the Duke of Burgundy.
• Experiments were conducted on dead British soldiers in 1839 to determine “time since death.”
• In 1880 the first elimination of a suspect was done using fingerprints.

The list goes on from there, and every day new discoveries are made to amplify scientists’ knowledge in this field.

Are you a forensics fan?

 

Forensic Friday: Can You Smell That?

Dogs and humans are different. You probably already knew that. But did you realize just how different we are? Think about it. Humans primarily use sight as the way we process the world around us. Dogs, on the other hand, use their sense of smell to interpret their experiences.

Do you own a dog? What happens when you come home? My Boston Terrier, Ben, immediately jump off the couch and sniffs my pants and my shoes. If I bend down to greet him, he sniffs my blouse, face and any other area he can reach. If he could talk, he’d tell me exactly what I had been doing all day.

How is that possible? Well, a human has about five million scent glands as compared to a dog who has anywhere from 125 to 300 million scent glands. Therefore, a dog’s sense of smell is 10,000 to 100,000 times better than our own. According to James Walker, former director of the Sensory Research Institute at Florida State University, "If you make the analogy to vision, what you and I can see at a third of a mile, a dog could see more than 3,000 miles away and still see as well." I don’t know about you, but that is mind-boggling to me.

According to searchandrescueassist.org, dogs have been doing search and rescue for three hundred years. It all began with the St. Bernards of the Monks of the Hospice in the Swiss Alps. The dogs were trained to locate travelers who had become stranded or lost in winter storms while crossing the passes between Switzerland and Italy.

Search and rescue dogs can be broken into two categories: air-scenting dogs and trailing (or tracking) dogs. Air-scenting dogs primarily use airborne human scent to home in on subjects, whereas trailing dogs rely on scent of the specific subject. Specific applications for search and rescue dogs include wilderness, disaster, avalanche, drowning, and cadaver recovery. Cadaver dogs can locate entire bodies (including those buried or submerged), decomposed bodies, body fragments (including blood, tissues, hair, and bones), or skeletal remains; the capability of the dog is dependent upon its training.

In the United States a volunteer civilian organization, Dogs for Defense, helped convince the military to use dogs by training sentry dogs for the military to try out. In 1942 the Army authorized DFD to train 200 sentry dogs. Later the military took over the training, and DFD was appointed the sole procurement agency for the Armed Forces. Dogs were trained as sentry dogs, message carriers, sled dogs in the Arctic, and scout dogs.

Not surprising that dogs are referred to as Man’s Best Friend!

Got a favorite dog story to share? I’d love to hear it.

CSI: The Early Years

As part of my blog re-launch, I'll be running some of my past posts. Here is one of the more popular ones:

More than 2,000 years before William Peterson or Marg Helgenberger prowled Las Vegas to collect evidence and solve crimes, the attending physician for Julius Caesar stated that of the 23 wounds on his body, only one was fatal. Fast forward to 1247 when the first textbook of forensic medicine was published in China. Nearly 400 years later the first book on document examination was published in France. The wheels of progress ground slowly until 1829 when Scotland Yard was established - a mere six years later the Yard used the first bullet comparison to catch a murderer.

After that the discoveries came fast and furiously. Here are just a few:

• 1836 – James Marsh develops a test for arsenic in tissues
• 1853 – First test for hemoglobin
• 1863 – First published paper on time-since-death determinations using temperature
• 1883 – Alphonse Bertillon invents anthropometry to identify and differentiate criminals
• 1891 – First book published describing the use of physical evidence to solve crimes
• 1892 – Francis Galton classifies fingerprints into the basic patterns that are still used today

Enter the computer. Thanks to technology, information can now be collected in

databases and shared across borders. One such database is IAFIS - the Integrated Automated Fingerprint Identification System – the national fingerprint and criminal history system. It is the largest biometric database in the world, housing the fingerprints and criminal histories for more than 70 million subjects in the criminal master file, along with more than 34 million civil prints. According to fbi.gov the average response time for IAFIS is 27 minutes. Compare that to the weeks or months spent combing over paper records in the past and consider that in 2010 IAFIS processed over 61 million submissions!

But wait! There's more. About twenty five years ago, the use of DNA matching became an integral part of solving crimes, and in 1995 the world's first national DNA database was set up in the UK. The US followed a short time later, and thanks to this wonder of science criminals have been caught, cold cases have been solved and innocent people have been released from prison.

I'll never look at those sticky fingerprints on the kitchen counter the same way again! How about you?