25 Surprising Facts About Forensic Science

You’ve seen all the crime-based TV shows - Law and Order, Medical Detectives, CSI and all its versions - and you think you’ve got a pretty good idea of what forensic science is all about. Think again.

Real-life forensic science is quite different from fictional televised accounts, but it’s every bit as fascinating. Here are 25 things you probably never knew about real-life forensic science:



1. Forensic Science Wasn’t Invented by Scientists

Although its methods are highly scientific, forensic science owes its beginnings to cops who relied heavily on observation and common sense. Police officers using fingerprints to identify culprits led to forensic science as we know it today. The most impressive advances, such as DNA testing and UV light screening, came into the picture much later, when technology was more advanced. The practicality of investigators in the past is responsible for modern scientific forensic methods.

2. Fingerprints Aren’t Foolproof

In movies and on television, once a fingerprint has been discovered at the crime scene, it’s only a matter of time until the criminal is caught. A fingerprint seems to be the most damning piece of evidence that can be used against an individual. Real-life forensic scientists will tell you, however, that while each person does have unique fingerprints, matching them can be difficult, even for experts.

Although fingerprints are distinct among individuals, their patterns are so intricate and variable that it takes a well-trained eye to recognize a match. Computer technology has made this process a lot easier, but seasoned forensic scientists note that there is no completely foolproof statistical formula for matching fingerprints.

3. Bullets Aren’t Foolproof Either

As with fingerprints, ballistics and bullet markings are not easily matched. The barrel of each gun has its own unique grooves and surfaces, creating a distinct imprint that acts as the “fingerprint” of the gun. As the bullets shoot out of the gun, they fly through the barrel and are marked by that imprint. While this ballistics theory is sound, the process of actually finding a match for the gun and bullet has no strong statistical formula behind it.

When you consider the fact that a bullet can be damaged upon impact, finding a matching pattern becomes even more difficult. Although authorities have been able to trace weapons from the bullets they fired (and from those who fired the weapons), the process itself is extremely meticulous and open for error. Ballistics specialists must therefore be precise with their analysis.

4. DNA Testing Saves Lives

To date, DNA testing has exonerated more than 242 wrongfully-convicted individuals. Thanks to advances in DNA technology, questionable convictions are sometimes re-investigated using DNA testing. Should the evidence show that the defendant could not have committed the crime, he or she can successfully be exonerated.

Because of this, there are several organizations pushing for the requirement of DNA testing on all convicts. No one knows exactly how many innocent citizens are wrongfully convicted, so many individuals strive to right this wrong.

5. DNA Testing Makes Mistakes

Unfortunately, the reverse can also happen. DNA testing has never been 100% accurate. There have been more than 50 false incriminations based on faulty testing. DNA testing is a precise science, and a single mistake can lead to the wrongful conviction of innocents. Although the odds of error in DNA testing are relatively low, the possibility of mistaken results does exist.

6. Teeth Are Trustworthy

What piece of crime scene data is responsible for identifying over 93% of remains? Dental records. Because bones are among the sturdiest parts of the body, they are often the best-preserved area in remains. Combine this with the fact that every individual has a unique dental imprint, and you have the recipe for an extremely reliable form of identification.

Identification by dental records is especially useful in cases where the victim was left unrecognizable. Crimes that involve mutilation, burning, or any other form of disfigurement may still leave the teeth relatively intact. Samples procured from teeth can be matched to existing dental records to help identify the body.

7. Bugs Are Good For You

While maggots on a corpse may be disgusting to some these critters are a welcome sight to forensic scientists. Insects have proven to be a reliable indicator of an individual’s time of death. There is an entire field of forensic science dedicated to the study of insects in the crime scene – forensic entomology.

Insects can provide even more information. The times at which the insects were known to have been active can tell investigators when the crime occurred. Because insects also exhibit a certain level of endemism (the tendency to live only in certain areas), bugs present in the corpse can help tell scientists where the crime was committed. This helps investigators determine whether the body was moved from the actual crime scene post-mortem.

8. The Nose Knows

Dead bodies emit certain smells when they die, often to the revulsion of many. These pungent aromas are actually a combination of chemical gases emitted by the corpse, like ammonia and sulphur. Scientists are currently working on machines that will be able to detect these chemical gases, thereby determining where a corpse may be found. Such a machine would give crime scene investigators another method of locating dead bodies in addition to traditional, conventional methods.

9. Deleted Computer Files Aren’t Always Gone

Savvy forensic scientists may be able to find evidence that’s been deleted from a computer. Every time you “delete” a file from a computer, the file is simply set aside, hidden, and marked as data waiting to be rewritten. Computer analysts use this fact to their advantage and have developed programs that detect these hidden files, allowing them to copy and open the data.

10. Forensic Science Comes Second

Despite its reputation, forensic science, is only the second best method of identifying criminals. What’s number one? Eyewitness account, of course. Eyewitness testimony far outweighs the deductions based on forensic scientific methods. It’s much easier to believe someone who’s actually witnessed a crime than the educated guesses of several scientists.

Witnesses have been known, however, to provide unreliable accounts of the crime. Fear or panic can cause people to recall things differently from what they actually saw. Many variables affect the credibility of eyewitness testimony, including poor lighting and quick movement. Investigators often use forensic science to corroborate the stories of the eyewitnesses. If evidence produced by forensic methods helps an eyewitness recognize certain facets of the crime, then their testimony is strengthened.

11. Color Counts

The gravitational pooling of blood, called livor mortis, can indicate a victim’s time of death by analyzing the discoloration in the lowest point in the body. Livor mortis occurs shortly after the victim has died and the circulatory system has shut down. At this time, the blood will flow towards the part of the body closest to the ground, where gravity is most concentrated. As the blood accumulates, that area will swell slightly and become discolored. Forensic investigators can calculate time of death by measuring the amount and size of discoloration and comparing it with the physics behind the flow of blood.

12. The Nose Knows, Part 2

In cases of arson, one of the most crucial points of the investigation is learning how the crime was carried out. Everything, from the fire’s point of origin to the manner in which the fire was started, is essential in determining if it was indeed arson.  From the same information, investigators can get a clue as to who committed the crime.

Investigators must also learn how the fire was spread. Arsonists often use chemicals that have distinct scents to do their dirty work. Investigators use sniffers to help identify what type of substance was used to accelerate the spread of fire. Scents they particularly note include gasoline and kerosine.

13. Fingerprinting is Older Than You Think

Long before police were collecting fingerprints for evidence, another culture was already using the unique grooves on a person’s fingertips to identify him. The ancient Chinese used thumbprints instead of signatures on legal documents.

In ancient times, only the elite were privileged enough to receive an education. The ability to read and write was usually confined to the royalty and the priesthood. This created problems, however, when one of the regular citizens had to sign a legal document. Rather than taking the time and effort to teach that person how to write his name, authorities decided that thumbprints were a viable alternative to signify identity.

14. Everything You Do on the Internet Is Tracked.

Internet tracking is one of the easiest forms of surveillance. The Internet is a vast public area, where everyone is connected to everyone else– this includes the authorities. If they wanted to, the government could watch the Internet activity of anyone, just as they are tracking many people at this very moment. Every site you visit, every single mouse click and press of the keys , can be traced by a knowledgeable computer technician. The government has taken advantage of this fact and hired several such individuals to monitor citizens, especially those under suspicion of criminal activity. Known convicts are closely monitored after their release to prevent the commission of further illegal activity.

15. Analysis Isn’t As Easy As You Think

On TV crime dramas, once a piece of evidence has been retrieved, the results of testing will soon follow. In reality, however, actual testing is a slow and deliberate process that can take weeks, even months. Most television shows last around 25 to 45 minutes, so the results of their fictional forensic tests are back quickly.  The rule of thumb is, the more technical the forensic test, the longer it will take. For example, while a run-through of fingerprints can take a few minutes, DNA testing can go on for days, even weeks. Certain measures are taken to improve the accuracy of the tests, while increasing the time. These tests must be performed precisely — otherwise the odds of faulty results being obtained increase.

16. Forensic Scientists Can Learn From You

While textbooks and theories teach budding forensic scientists the tricks of the trade, there’s no substitute for actual experience. Many looking to enter the field of forensic science try to involve themselves in actual crime investigations, either through apprenticeship or through internship. Not all students are lucky enough to join in on police investigations, however, and the best way they can learn is by studying real-life dead bodies. Although this may seem revolting to some, this type of study is quite appealing to students of forensic science. It greatly enhances their learning experience. If you’d like to help them out in their endeavors, an institution known as the Body Farm can help you arrange to have your body donated to forensic science after your death.

17. There Is No Perfect Piece of Evidence

Contrary to what TV crime shows may lead you to believe, most of the evidence found at crime scenes is usually contaminated, sometimes even rendered unusable. By the time the authorities arrive, the crime scene will have already been contaminated by several uncontrollable variables, such as the weather and passersby. The evidence may have been moved, altered, or even broken, depending on the speed of the response of the investigating team.

Evidence at violent crime scenes can be even more difficult to pin down. Physical confrontations can cause evidence to break, shattering into minuscule pieces. Blood can stain and soak certain materials. Explosions can literally disintegrate valuable information. Add to this the fact that many criminals are smart enough to try to conceal their work, and finding good pieces of evidence suddenly becomes an extremely challenging task.

18. Forensics Time Travels

Forensic science is often used to shed some light on cold cases, or past cases that were previously declared unsolvable. One such cold case involves the case of Dr. Hawley Harvey Crippen, a man convicted of murder back in 1910. Crippen was found guilty of murdering his wife Cora, who disappeared one day , only to have her remains found hidden underneath the cellar floor of Crippen’s home. He was then apprehended, tried, and sentenced to hang.

However, in 2007, a forensic scientist from Michigan State University discovered that mitochondrial DNA samples from the corpse did not support the claims that the body found underneath Crippen’s cellar belonged to Cora Crippen. As a result, the case of Dr. Hawley Crippen has once again become open to questioning.

19. The Earth Loves Forensics

Humans aren’t the only ones to benefit from forensic science. Numerous eco-crimes have been resolved, thanks to the endeavors of forensic scientists. Mismanagement of hazardous waste, large-scale industrial pollution, and other serious eco-crimes can now be solved through the efforts of forensic scientists. By tracing the chemical signatures of the contaminants found in the areas of incident, the individuals responsible for many ecological wrongdoings have been caught by the authorities. The mercury poisoning in the true-to-life film “Erin Brockovich” was eventually traced to its source through a combination of investigative know-how and perseverance.

20. Fingerprints Streamlined Identification

Long before fingerprints became the norm for identification, authorities used bertillionage, an arduous process that entailed taking 11 different bodily measurements, including: height, length of the body from the left shoulder to the tip of the middle finger in a raised right arm, length of the torso from head to seat when in a seated position, length from the crown to the forehead, length between temples, length of the right ear, length of the left foot, length of the left middle finger, length from the left elbow to the tip of the left middle finger, the width of the cheeks, and the length of the left pinky.  After all of that, the officers would then have to cross-reference these measurements with their records for a perfect match. This was a very effective, though inefficient, process.

Today, authorities simply need to run an image of the suspect’s fingerprints through a computerized record, and a match will be found within minutes.

21. You Can’t Lie Through Your Teeth

One of forensic science’s strangest pieces of incriminating evidence involved the crimes of Ted Bundy, one of history’s most infamous serial killers. His modus operandi was to violently bludgeon an innocent victim to a helpless state, and then strangle her to death. After his capture, he confessed to having killed over 30 women, although many believe that his actual body count was over 100.

Despite the blatant savagery of his crimes, Bundy was a highly intelligent man. He was able to skirt the law, and was not found guilty throughout 10 years of questioning. However, one piece of evidence proved beyond a shadow of a doubt that Bundy was indeed responsible for the heinous murders. He was found guilty based on dental matches to bite marks he left on the buttocks of one of his victims!

22. It’s All In Your Head

One of the best indicators of race is cranial morphology, or skull shape. Hawaiians, for example, have a characteristic jaw that rocks back and forth if pushed (known as Rocker Jaw). The shape of the skull can also tell investigators a victim’s gender. Males have slightly sloping foreheads, whereas females’ foreheads are vertical. Details such as these help investigators analyze and identify remains. This information can be used for a variety of purposes, such as gaining insight into the criminal’s modus operandi, and to notifying an identified victim’s relatives of the unfortunate circumstances.

23. Hay Fever Can Be Incriminating

Forensic Palynology is the study of pollen and spores, which tend to stick to a criminal’s body and/or clothing and can be used as an indicator of his whereabouts, based on areas where that particular plant grows. Pollen can land on the culprit through a variety of means, such as wind, insects, or gravity bringing pollen down from overhanging plants. Should this occur, any traces of pollen found on a suspect can be used to link him to the scene of the crime.

24. Forensic Science is Old

One of the first accounts of forensic science being used to solve a crime occurred in 44 B.C., when Julius Caesar was stabbed to death by Roman senators. A physician named Antistius was called to study the corpse of Julius Caesar. Upon examination of the body, Antistius concluded who was responsible for the crime, and the guilty senators were sentenced to death. The physician made his fateful announcement in the Roman forum, giving forensic (forensic – from the Latin forensics, “belonging to the forum”) science its name.

25. Fingerprint Identification Has Come a Long Way

Matching fingerprints wasn’t always as easy as it seems to be on TV. Most law enforcers now use the Automated Fingerprint Identification System (AFIS), a program that matches a fingerprint to a record within minutes or even seconds. With its high degree of accuracy, fingerprint identification isn’t quite as complicated, or as tedious, as it used to be. Before the creation of the AFIS in 1970, officers would have to rifle through millions of cards and records to find a match.


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