As a result of social changes there have been subtle and gradual changes to our skeletal make-ups, making the work of a forensic anthropologist difficult. Those once clearly defined markers on the skull (as well as the rest of the body) are becoming less definitive. It is the responsibility of scientists to grow with the times and expand their arsenal of examination in light of these events.

For many years, it has been posited that the frontal sinus pattern in the human skull is unique to an individual, similar to the idea that fingerprints and DNA are unique. In 2008, a study was published in the Journal of Forensic Science by Roberto Cameriere and colleagues, that sought to test the accuracy of this position. They also sought to measure the rate of false positives between persons that were closely related (kin) to better understand the strengths of using sinus patterns to truly identify human remains.

Cameriere x-rayed skulls of 99 individuals from 20 families between the ages of 15 and 74 (from Northern Ireland). This enabled the scientists to test the effect of closely related persons for false positives. After all the skulls were radiographed and digitally imaged with both anterior (front) and posterior (back) views, they were then statistically analyzed. They used functions and probability to measure the rates of false-positives within their sample.

The results showed that even when examining individuals from the same family group the probability of falsely identifying is very small. They also posited the rate for a false positive did not change significantly when family relation was a factor. This research and its results can be helpful when trying to solve cases [especially with=”” closely=”” related=”” kin=””][/especially] where other heavily relied upon identifying methods (DNA fingerprints, etc.) are inconclusive. These results can provide a level of comfort to the scientist(s) attempting to make identification and serve to improve accuracy in tough cases.

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Many of the forensic accomplishments that are seen on TV are just not possible with current technology, but could be sometime in the future. For example, we currently do not have the technology to definitively match an unknown fingerprint or bullet casing to one that is in a computer database of known criminals or crimes. The database will give us some possible matches but it is not able to actually find an undisputed match. A trained examiner is responsible for ultimately making the identification from the possible matches the database has produced. If a computer could actually get to that standard of analysis it could save the examiners a great deal of time. Of course legally an examiner would most likely still have to verify the computer’s work.

In the future there may also be new techniques and methods for dusting for and lifting fingerprints, such as what is being accomplished with gel lifters. The gel lifters have recently been introduced to forensics in the United States and are able to lift prints from surfaces that have historically been impossible to lift prints from. There may also be new chemicals or methods to detect if there is blood or even DNA at a crime scene. These possible advancements all depend on the research of scientists working today.

There are more and more people going to school to pursue a career in forensics. They range from the crime scene investigator to the forensic accountant. If you are interested in forensics but not all of the science that often accompanies it, try to see if there is a way to relate your particular area of study to crime solving. Forensic science is really any discipline that you can relate to the law, so even though being an accountant is not really a “science” it is part of forensics because it can be used to solve a case.

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If you missed your chance to come to the week-long camp, now’s the time to make up for it! Sign up now at our camp website–that’s also where you can find details on the camp itself. Hope to see you there!

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November 24, 2011 will be the 40th anniversary of the time a man calling himself Dan Cooper (D.B. to the press) hijacked an airplane and managed to get $200,000 and parachutes in exchange for the passengers’ lives. Since he parachuted into the night no one has knowingly seen or heard from him, and the case is still unsolved–the only unsolved skyjacking in US history.

If the newest D.B. Cooper lead pursued by the FBI pans out, D.B. may actually turn out to be a Cooper. D.B. may have plotted the hijacking within earshot of his 8-year old niece Marla–as Marla Cooper herself claims.

The difficulty in proving the claim is the same as any cold case: there is very little physical evidence available. It’s made more difficult by the fact that, according to the family, Cooper’s been dead for over a decade. The FBI is working on matching his fingerprints to some found on the plane. While D.B. touched a number of items on the plane that maintained fingerprints, he was not the only person to do so, and separating the hijacker’s prints from the rest has been difficult, even with the family’s cooperation in providing items owned by the new suspect.

For more on the developing story, see here.

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The system worked quite well, until 1903 when Will West was received at Leavenworth Penitentiary. Upon running Will West’s measurements, it was discovered that a “William West” was already imprisoned at Leavenworth.  He had the same anthropometric measurements as Will West.  A photographic comparison of the two men did little to distinguish them.   Finally, two years after Will West was brought to Leavenworth, fingerprints of each man were taken, compared, and found to bear no resemblance.  Thus each man was distinguished by his fingerprints.  Needless to say, Leavenworth converted from the Bertillon system to the more reliable fingerprint system, which is still in use today. This is a reminder that fingerprints are important.

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Both New York and Maryland have computerized ballistic fingerprint databases, both states have legal mandates that require all firearms manufacturers to provide, a spent cartridge and prepare ballistics images of the bullets and cartridge casings and provide the records so that the state’s law-enforcement agencies can access it, for every firearm legally sold; the law also requires that the name, address and Social Security number of the person purchasing the firearm be linked to the ballistics information.

The law, and the database, is based on the theory that that every gun marks shells and bullets in specific, stable, identifiable ways.  The reason casings are used is because firearm that produce marks on cartridge cases are less subject to long-term wear.  This theory, unfortunately, has not been scientifically proven.  In fact, the markings left by a gun on a casing are not guaranteed to be the same over the long term and can be deliberately changed with simple tools such as a file or metal brush.

Another problem with the ballistic fingerprint database, as it stands, is that only new gun purchases are beholden to the law, meaning that the millions of already purchased guns cannot be traced via the database.  Other concerns include the fact that less than 1% of legally guns sold will ever be used in a crime, guaranteeing wasted effort.  Beyond that, nearly 90% of guns used in crimes change hands at least once after their initial purchase at a licensed dealer before being used in crimes; it has been estimated that nearly 40% of guns used by criminals are either stolen from their rightful owners or purchased on the black market.

There is also fault with the potential usefulness of such a database.  California did some extensive testing to assess the accuracy of such a database and they found that when shell casings used with a particular gun came from the same manufacturer the computer failed to match the correct casing to its gun 38% of the time; when casings came from different manufacturers the failure rate was 62%.  These false matches waste the time of ballistic examiners who are left ruling out matches made by the computer database. New York has had its database up and running since 2002 and has since entered data from over 200,000 new gun purchases and has spent approximately $1,000,000 a year on its system. By 2007 the system had not led to a single solved crime.

Fingerprint and DNA databases see their success from the fact that neither identifier is subject to change, a person is stuck with the DNA and fingerprints they are born with, but this is not the same for a gun and its parts. The parts of the gun that are responsible for marking a shell casing are the breech face, extractor, ejector, and firing pin, all of which can be purposefully altered with specific tools or all of which may change with time and normal wear.  Although the idea of a ballistic database is appealing given the large amount of gun violence in the US, unfortunately the ease with which guns can be altered appears to throw a monkey wrench in the idea.

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For the process for super glue fuming to occur, the cyanoacrylate must be boiled to achieve its gaseous form.  Once in a gaseous state, the fumes will slowly circulate in the chamber and will engulf the room.  If any latent fingerprints exist on the object being fumed those prints will be exposed to the gaseous cyanoacrylate triggering a chemical reaction. The reaction can take from 5 minutes to over two hours with the exact time determined by the size of the chamber as well as the concentration of the gaseous cyanoacrylate in the air and the humidity of the environment. Care must be taken with cyanoacrylate fuming because when latent prints are exposed to the super glue fumes for too long they can over develop and lose essential detail.

After the fingerprints are developed using the super glue fuming method they can generally last for years; cyanoacrylate fuming can be used to preserve fingerprints since the glue fumes coat latent prints with a hard surface making them harder to accidentally alter or destroy.  Cyanoacrylate fuming also does not preclude DNA testing on items that have been exposed to the fuming process, any blood that has been exposed to cyanoacrylate fumes can still be successfully tested for a DNA profile.  Another positive aspect of super glue fuming is that it is not expensive, the only things required for cyanoacrylate fuming are a bottle of super glue, a heat source, and a chamber to enclose the fumes; many departments use plastic bags as chambers when fuming at a crime scene.

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Fingerprint residue contains natural salt secretions that corrode metals at the points where the salt contacts the metal. This microscopic fingerprint corrosion leaves a permanent mark on metal that cannot be washed away. The heat of the firing of the gun also does not alter these marks.

The new technique that has been established to visualize these types of prints relies on running electrical current over the metal object , such as a bullet casing or a gun, that has been coated with a fine toner like powder. When a charge is run down the metal object the fine conducting powder is attracted to these areas of corrosion revealing a powdered fingerprint.

This technology can also be used in fires to recover prints of metals exposed to very high temperatures.

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Now a public figure, Dillinger turned to plastic surgery to alter his identity and evade Purvis and the rest of the law enforcement community. In those days, plastic surgery was not as common as it is today, and the medical procedures were primitive, dangerous, time-consuming and very painful. Dillinger underwent several bouts of plastic surgery, some more successful than others, but in the end he only managed to slightly alter his appearance. After one round of plastic surgery from which he was extremely disappointed to find that he still looked the same, one of the doctors suggested that he remove his fingerprints as a way to escape being detected. Dillinger liked this idea and elected to undergo the painful process of obliterating his fingerprints.

A wanted poster for Dillinger, complete with all ten fingerprints

Dillinger was not the first criminal to come up with that idea. In 1933, “Handsome Jack” Klutas had attempted to file down the small ridges on his fingers, but he ultimately failed. Two of Kate “Ma” Barker’s clan, Alvin “Creepy” Karpis and Ma’s son Freddy, decided to remove their fingerprints as well, so they hired mob physician Joseph P. Moran to do the job. Moran was inexperienced in this procedure and repeatedly hacked and knifed at their prints until the gangsters couldn’t bear any more pain, but when their fingers finally healed, the fingerprint ridges grew back to their original patterns.

Hoover was aware of this trend among criminals and he became wary of the possibility of success. He commissioned several surgeons and dermatologists to report on the likelihood of someone obliterating their fingerprints, and in 1934 they came back with their findings. Dr. Howard L. Updegraff, a member of that committee, had extensive experience in the area of fingerprint alterations and he reported that the only way to permanently obliterate a fingerprint is to graft skin from another part of the body over them. And in 1941, that’s exactly what Robert Phillips did when he got a doctor to graft the skin from his chest on to the tips of his fingers. Phillips, however, was caught because the ridges surrounding the graft areas, as well as on the other joints of his fingers were used to identify him.

Dillinger seemed to have taken the road less traveled when he chose acid to burn the tips of his fingers with in late May, 1934. The procedure appeared to be successful; however, faint ridge markings were still visible on his fingertips after the full healing process, as were seen after Dillinger’s death.

Many people in American history have attempted to elude the authorities by scarring or ruining their fingerprints, but forensics has been able to keep up with those criminals all the while. In fact, as Phillips found out firsthand, just ruining the tips of one’s fingers does not preclude fingerprint identification. The ridges that are found on the tips of one’s fingers are also found on the entire surface of the palm, and they are just as unique to an individual. Furthermore, by introducing scars onto one’s fingers, it makes the identification process even easier, since the scar patterns are unique and less common to the general population.

If one thing can be learned from Dillinger and the other notorious outlaws of the Gangster Era it’s that crime does not pay, and eventually criminals will be brought to justice, and not always the pretty way.

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