Forensic Science
Forensic science has become a popular topic for television crime dramas and detective movies. Based on media portrayals, you might think that forensic scientists are only involved in solving crimes, especially homicides. However, forensic science has a much broader focus than just violent crime investigations.
Forensic science involves any science used by law enforcement and legal attorneys to provide evidence for courts of law. It is used in criminal investigations, civil law, and trials. There are strict guidelines for collecting, examining, testing, and reporting evidence. These rules are in place to ensure that the forensic evidence is accurate and reliable.
Chemistry
Chemistry is a science that identifies substances and their properties. Forensic chemistry is used to perform blood and fluid analysis, drug tests, fiber analyses, and tests for poison. For example, a forensic test can determine what substances are present in the blood.
Biology
Biology is the study of living organisms and their anatomy, behavior, and qualities. Forensic biology helps identify both victims and suspects using hair, bones, blood, and other body fluids.
Entomology
Entomology is a branch of zoology that studies insects. Forensic entomology uses insects found at a crime scene to identify the time when a crime was committed or identify a victim.
Physics
Physics is a science that focuses on matter and energy. Forensic physics helps to analyze soil samples and determine how fibers or glass were torn or broken. It is also useful in the process of photoluminescence, which helps to detect fingerprints.
Psychology
Psychology is the study of the human mind and behavior. Forensic psychology is used to explain behavioral aspects of a case or a person
Forensic Scientists and Technicians
These scientists and technicians practice forensic science. They help investigate crimes by collecting and preserving scientific evidence. They also perform laboratory analysis of collected evidence during the course of an investigation. Forensic scientists and technicians have more varied roles and specialties than we see portrayed in television shows.
Forensic scientists keep detailed logs and write reports about what they find. Attention to detail is critical, because a single mistake can result in evidence being thrown out of court. Forensic scientists are often called on to testify in court about their findings. Thus, it's important that they follow guidelines for testing evidence and maintain their professional integrity.
Application of Forensic Science
Forensic science plays an important role in modern law enforcement. If there are no witnesses to a crime, forensic evidence is all that prosecutors have to prove a case in a court of law. Forensic science labs are crucial, especially for drug-related and sex crimes where chemical or biological evidence are important in identifying the perpetrator.
Forensic science is also useful in civil law. For example, forensic scientists perform DNA tests to determine whether people are related. It is necessary in paternity tests, which are sometimes ordered by courts to determine child support payments and child custody.
In cases involving forgery, when someone creates a fake item (such as a rare painting) and tries to pass it off as real, forensic scientists test items to determine authenticity using chemistry. Forensic scientists also use chemistry to perform drug tests for athletes to reveal any illegal substances in the blood. Forensic science equipment is also useful during blood alcohol testing during routine traffic stops.
Apart from scientific activities, forensic scientists may also help track accounting fraud. This is the falsifying of accounting records to steal money or lie about finances. Forensic accounting uses accounting concepts and forensic investigative policies to track down perpetrators of fraud.
Limitations of Forensic Science
While forensic science has made great strides in the collection, testing, and analysis of evidence, it does have limitations. Let's take a look at some examples of limitations discovered in recent years.
Fingerprinting
According to the National Academy of Sciences (NAS), which is responsible for determining forensic rules and established criteria, fingerprints are not as unique as people may think. Forensic fingerprinting, known as friction ridge analysis, involves the study of ridges, loops, whorls, and points of similarities in prints. With a perfect fingerprint, identifying a criminal is reliable, but partial prints are limited in usefulness. After the March 2004 Madrid terrorist bombings, the FBI found a partial fingerprint on the bomb equipment that they identified as belonging to an Oregon lawyer named Brandon Mayfield. Later, it was determined that the print really belonged to an Algerian man named Daoud Ouhnane. This is a prime example of limitations in fingerprinting science.
Bite marks
Forensic bite mark comparison is the most controversial technique in law enforcement. Bite marks left on victims can distort over time because of swelling and healing. Comparing bite marks to dental records to identify criminals is therefore not an accurate science. This was shown in the case of Levon Brooks and Kennedy Brewer, who were both wrongfully convicted of a crime. In 1992, Brooks was convicted of rape and Brewer was convicted of murder. In both cases, the forensic dentists who testified in court wrongfully stated that their dental records matched distorted bite marks. In 2008, both Brooks and Brewer were proven innocent by new forensic findings and freed from jail.
Ballistics
Forensic technicians are called to crime scenes to determine bullet trajectory, which is the path that a bullet travels. These experts are often called into court to testify where a bullet came from and what firearm was used to commit the crime. However, the NAS has found that while bullet trajectory is reliable, determining the specific firearm used is not as simple. NAS states that a forensic expert may offer an "opinion" about what firearm was used, but the expert cannot state it as a scientific fact. This is because bullet patterns from firearms are not 100 percent reliable.
Forensic hair examination
The NAS has stated that hair cannot definitively identify someone at a crime scene. This is because characteristics found in hair are shared by a large portion of the population. The NAS states that there are no standards for matching a single hair to just one person, which is contrary to what is shown on forensic crime shows.
Criminalistics
Criminalistics is a specific discipline within forensic science. It is the study of physical evidence from a crime scene. Criminalists use investigative skills to separate important evidence from trivial evidence found by forensic scientists. This job may not sound important, but a mistake can wrongly convict an innocent person of a crime or let a guilty person go free.
Criminalists typically have a bachelor's degree in physical, biological, or forensic science. They may have additional training so they can identify, sort, and compare evidence for use in an investigation and subsequent trial. Another aspect of a criminalist's job is to interpret evidence and identify how a crime was committed.
History of Forensic Science
Forensic science wasn't always as structured or precise as it is today. The earliest application of forensic science occurred in ancient Greece and Rome.
Archimedes, a famous Greek scientist, invented a method for measuring an object's volume. In 275 BC, Archimedes was called on to investigate whether the king of Syracuse's golden crown had been replaced with a forgery by the local goldsmith. By measuring the volume of the king's golden crown and comparing it to the volume of actual gold, Archimedes proved that the goldsmith had indeed stolen the king's gold and replaced it with a forgery. In 44 BC, the first autopsy was performed on the Roman ruler Julius Caesar.
Later, in the eighth century AD, Chinese people started collecting fingerprints to solve crimes. In 1247, the book Hsi Duan Yu or The Washing Away of Wrongs was printed in China. It detailed forensic methods that would help solve crimes. The book was the first document to provide guidelines for scientific investigations. It inspired Doctor Bartolomeo da Varignana of Bologna to convince Italian legal authorities to approve autopsies as part of criminal investigations in 1302.
In England during the fifteenth century, the first forensics textbook was written. It introduced scientific methods to identify murder weapons. For example, a murder was committed using a sickle, which is a farm tool used to cut down crops. The trial judge confiscated all the sickles in the village, and the sickle that attracted flies was determined to be the murder weapon. This case was solved based on forensic techniques outlined in the book. It was an important early step towards relying on science to determine guilt.
Another murder case in 1784 was solved solely using forensics. In this particular case, a torn piece of newspaper in the murder weapon, a pistol, matched the paper in an Englishman's pocket. He was then convicted of murder.
Nineteenth Century Forensic Science
The 1800s brought about major progress in forensic science. Various scientific improvements enabled forensic science to become more exact and reliable. The first forensic test to determine the presence of blood on an object was the crystal test for hemoglobin. This test used hemin crystals. Later, the first bullet comparison was used to catch a murderer. Scientists also started applying toxicology, the study of the effects of chemicals on living things, to determine murder by poison. In addition, investigators began taking photographs to document evidence and identify criminals during this period.
In 1888, forensic science helped identify the victims of Jack the Ripper in London, England. He was arguably one of the most infamous serial killers in history. Autopsy doctors were able to connect the victims based on wound patterns. Although Jack the Ripper was never identified, this was the first internationally famous case that relied on forensic evidence to track a killer. This was ground breaking at the time, because the case served to increase the integrity of and reliance on forensic science.
Twentieth-Century Forensic Science
The twentieth century saw major improvements in education for forensic science. Prior to this period, forensic scientists were self-taught and relied on various books to guide them through procedures. There were no special schools or formal training available, which meant that forensic procedures were not uniform.
In 1902, Swiss professor R. A. Reiss (University of Lausanne, Switzerland) was the first person to attempt to establish forensic science as its own academic discipline at an established university. In the 1930s, the idea of criminal science caught on and US universities began to offer courses in forensic and political science. This led to the creation of the American Academy of Forensic Science (AAFS) in Chicago.
1920
Law enforcement started making bullet comparisons by using a comparison microscope. This became a common practice.
1931
The absorption-inhibition ABO blood typing technique was developed. It helped law enforcement narrow down potential criminal suspects.
1975
Frits Sernike, a Dutch physicist, invented the first interference contrast microscope. It allowed scientists to look at cell structure.
1984
British geneticist Alec Jeffreys discovered DNA fingerprinting. This technique enabled law enforcement to identify criminals, identify paternity, and overturn wrongful convictions of innocent people.
1994
A DNA databank was established. This enabled law enforcement to check crime scene DNA against the DNA of known offenders who were previously convicted of a crime.
Twenty-first-Century Forensic Science
During the nineteenth and twentieth centuries, forensic practices like photographing crime scenes and performing DNA analyses were revolutionary concepts. They became common practice in forensic crime labs. Today, courts and law enforcement recognize forensic science as a critical part of solving crimes.
Forensic experts are called upon to deliver expert testimony on evidence analyzed in forensic crime labs. Modern crime labs have the benefit of new technology like 3D forensic facial reconstruction software, which takes human remains and creates a picture of what the victim looked like prior to death. Today, law enforcement also has access to forensic carbon dating and DNA sequencers. These help identify criminals based on hair, skin, and body fluid samples. Law enforcement personnel also have the Automated Fingerprint Identification System (AFIS), which allows them to compare fingerprints found at crime scenes with a virtual database of fingerprints from across the country.
As advances in technology and discoveries in science develop, the field of forensic science continues to improve and expand.
Famous Forensic Scientists
The progress of forensic science over the past few centuries would not have been possible without the discoveries and work of some brilliant scientists.
Mathieu Orfila (1787-1853)
Orfila was a French toxicologist and chemist. He established toxicology, which is the scientific study of chemicals in humans and other living things. He also created a method for detecting arsenic in murder victims. Hence, he is called the Father of Toxicology.
Francis Galton (1822-1911)
Galton was an English geneticist, psychologist, anthropologist, and inventor. He published papers on heredity and the racial profiling of fingerprints. Galton created a classification system for fingerprints that is still used today. He was responsible for convincing courts of law that fingerprints were valid evidence and strong enough to warrant convicting someone of a crime.
Dr. Joseph Bell (1837-1911)
Bell was a Scottish professor of clinical surgery. He was the teacher of the famous author Sir Arthur Conan Doyle. He was also the inspiration for Doyle's Sherlock Holmes character. Bell was able to diagnose patients and guess their professions at first sight based on immediate observations (just like the detective Sherlock Holmes). He was famous for his deductive reasoning, which helped give forensic science further credibility.
Alphonse Bertillon (1853-1914)
He was a French policeman and biometrics researcher. Bertillon created forensic techniques like forensic document examination. He also pioneered the use of galvanoplastic compounds as molds for footprints and ballistics in order to preserve evidence. Bertillon also created a system based on photographs of the same person over time to study physical differences with age.
Edmon Locard (1877-1966)
Locard was a forensic scientist known as the "Sherlock Holmes of France." He created the basic principle of forensic science, which states, "Every contact leaves a trace." He spearheaded the idea that every crime scene is full of evidence.
Calvin Goddard (1891-1955)
He was a forensic scientist from Baltimore, Maryland. Goddard was famous for pioneering the field of forensic ballistics. Hence, he is called the Father of Ballistics. In 1929, he helped solve the St. Valentine's Day Massacre.
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