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Forensic science: the story on HearLore | HearLore
Forensic science
The first written account of using science to solve a crime appeared in 1248, not in a modern laboratory, but in the courtrooms of Song dynasty China. Song Ci, a director of justice, jail, and supervision, published the book known as Washing Away of Wrongs, which introduced regulations for autopsy reports and methods to protect evidence. He devised techniques to make antiseptics and to promote the reappearance of hidden injuries on dead bodies using sunlight and vinegar under a red-oil umbrella. In one famous case described in the book, a person was murdered with a sickle. An investigator instructed each suspect to bring their sickle to a single location. Flies, attracted by the smell of blood, gathered on a single sickle, leading the owner to confess. This ancient method of using entomology to solve criminal cases predates modern forensic science by centuries. Song Ci also explained how to distinguish between suicide and faked suicide, and how to determine if a death was caused by drowning or strangulation by examining the lungs and neck cartilage. His work established the principle that all wounds or dead bodies should be examined, not avoided, setting a precedent for impartiality in forensic investigation.
The Birth of Modern Pathology
In 16th-century Europe, medical practitioners in army and university settings began to gather information on the cause and manner of death, laying the groundwork for modern forensic techniques. Ambroise Paré, a French army surgeon, systematically studied the effects of violent death on internal organs. Two Italian surgeons, Fortunato Fidelis and Paolo Zacchia, laid the foundation of modern pathology by studying changes that occurred in the structure of the body as the result of disease. By the late 18th century, writings on these topics began to appear, including A Treatise on Forensic Medicine and Public Health by the French physician François-Emmanuel Fodéré and The Complete System of Police Medicine by the German medical expert Johann Peter Frank. As the rational values of the Enlightenment era increasingly permeated society, criminal investigation became a more evidence-based, rational procedure. The use of torture to force confessions was curtailed, and belief in witchcraft and other powers of the occult largely ceased to influence the court's decisions. In 1784, in Lancaster, John Toms was tried and convicted for murdering Edward Culshaw with a pistol. When the dead body of Culshaw was examined, a pistol wad found in his head wound matched perfectly with a torn newspaper found in Toms's pocket, leading to the conviction. This case demonstrated the increasing use of logic and procedure in criminal investigations at the time.
When was the first written account of using science to solve a crime published?
The first written account of using science to solve a crime appeared in 1248 in the courtrooms of Song dynasty China. Song Ci published the book known as Washing Away of Wrongs which introduced regulations for autopsy reports and methods to protect evidence.
Who developed forensic DNA analysis and when was it first used?
Forensic DNA analysis was first used in 1984 and was developed by Sir Alec Jeffreys. He realized that variation in the genetic sequence could be used to identify individuals and to tell individuals apart from one another.
What is the name of the test used to detect arsenic in corpses and who created it?
A method for detecting arsenious oxide in corpses was devised in 1773 by the Swedish chemist Carl Wilhelm Scheele. James Marsh was the first to apply this new science to the art of forensics and developed the Marsh test in 1836.
When did the first fingerprint bureau open and who created it?
Juan Vucetich set up the world's first fingerprint bureau in 1892 after studying Galton's pattern types. In that same year Francisca Rojas of Necochea was found in a house with neck injuries and her prints were matched to a bloody thumb mark on a door.
Who is known as the mother of forensic science in the United States?
Frances Glessner Lee is known as the mother of forensic science and was instrumental in the development of forensic science in the US. She lobbied to have coroners replaced by medical professionals and created the Nutshell Studies of Unexplained Death to train investigators.
What percentage of wrongful convictions contain forensic science errors according to the Innocence Project?
According to the Innocence Project and the US Department of Justice, forensic science has contributed to about 39 percent to 46 percent of wrongful convictions. The Innocence Project database of DNA exonerations shows that many wrongful convictions contained forensic science errors.
The French police officer Alphonse Bertillon was the first to apply the anthropological technique of anthropometry to law enforcement, creating an identification system based on physical measurements. Before that time, criminals could be identified only by name or photograph. Bertillon created many other forensics techniques, including forensic document examination, the use of galvanoplastic compounds to preserve footprints, ballistics, and the dynamometer, used to determine the degree of force used in breaking and entering. Although his central methods were soon to be supplanted by fingerprinting, his other contributions like the mug shot and the systematization of crime-scene photography remain in place to this day. Sir William Herschel was one of the first to advocate the use of fingerprinting in the identification of criminal suspects. While working for the Indian Civil Service, he began to use thumbprints on documents as a security measure to prevent the then-rampant repudiation of signatures in 1858. In 1880, Henry Faulds, a Scottish surgeon in a Tokyo hospital, published his first paper on the subject in the scientific journal Nature, discussing the usefulness of fingerprints for identification and proposing a method to record them with printing ink. He established their first classification and was also the first to identify fingerprints left on a vial. Returning to the UK in 1886, he offered the concept to the Metropolitan Police in London, but it was dismissed at that time. Faulds wrote to Charles Darwin with a description of his method, but, too old and ill to work on it, Darwin gave the information to his cousin, Francis Galton, who was interested in anthropology. Having been thus inspired to study fingerprints for ten years, Galton published a detailed statistical model of fingerprint analysis and identification and encouraged its use in forensic science in his book Finger Prints. He had calculated that the chance of a false positive was about 1 in 64 billion. Juan Vucetich, an Argentine chief police officer, created the first method of recording the fingerprints of individuals on file. In 1892, after studying Galton's pattern types, Vucetich set up the world's first fingerprint bureau. In that same year, Francisca Rojas of Necochea was found in a house with neck injuries whilst her two sons were found dead with their throats cut. Rojas accused a neighbour, but despite brutal interrogation, this neighbour would not confess to the crimes. Inspector Alvarez, a colleague of Vucetich, went to the scene and found a bloody thumb mark on a door. When it was compared with Rojas' prints, it was found to be identical with her right thumb. She then confessed to the murder of her sons.
The Chemical Revolution
A method for detecting arsenious oxide, simple arsenic, in corpses was devised in 1773 by the Swedish chemist, Carl Wilhelm Scheele. His work was expanded upon, in 1806, by German chemist Valentin Ross, who learned to detect the poison in the walls of a victim's stomach. James Marsh was the first to apply this new science to the art of forensics. He was called by the prosecution in a murder trial to give evidence as a chemist in 1832. The defendant, John Bodle, was accused of poisoning his grandfather with arsenic-laced coffee. Marsh performed the standard test by mixing a suspected sample with hydrogen sulfide and hydrochloric acid. While he was able to detect arsenic as yellow arsenic trisulfide, when it was shown to the jury it had deteriorated, allowing the suspect to be acquitted due to reasonable doubt. Annoyed by that, Marsh developed a much better test. He combined a sample containing arsenic with sulfuric acid and arsenic-free zinc, resulting in arsine gas. The gas was ignited, and it decomposed to pure metallic arsenic, which, when passed to a cold surface, would appear as a silvery-black deposit. So sensitive was the test, known formally as the Marsh test, that it could detect as little as one-fiftieth of a milligram of arsenic. He first described this test in The Edinburgh Philosophical Journal in 1836. Henry Goddard at Scotland Yard pioneered the use of bullet comparison in 1835. He noticed a flaw in the bullet that killed the victim and was able to trace this back to the mold that was used in the manufacturing process. The Uhlenhuth test, or the antigen, antibody precipitin test for species, was invented by Paul Uhlenhuth in 1901 and could distinguish human blood from animal blood, based on the discovery that the blood of different species had one or more characteristic proteins. The test represented a major breakthrough and came to have tremendous importance in forensic science.
The DNA Revolution
Forensic DNA analysis was first used in 1984. It was developed by Sir Alec Jeffreys, who realized that variation in the genetic sequence could be used to identify individuals and to tell individuals apart from one another. The first application of DNA profiles was used by Jeffreys in a double murder mystery in the small English town of Narborough, Leicestershire, in 1985. A 15-year-old school girl by the name of Lynda Mann was raped and murdered in Carlton Hayes psychiatric hospital. The police did not find a suspect but were able to obtain a semen sample. In 1986, Dawn Ashworth, 15 years old, was also raped and strangled in the nearby village of Enderby. Forensic evidence showed that both killers had the same blood type. Richard Buckland became the suspect because he worked at Carlton Hayes psychiatric hospital, had been spotted near Dawn Ashworth's murder scene and knew unreleased details about the body. He later confessed to Dawn's murder but not Lynda's. Jefferys was brought into the case to analyze the semen samples. He concluded that there was no match between the samples and Buckland, who became the first person to be exonerated using DNA. Jefferys confirmed that the DNA profiles were identical for the two murder semen samples. To find the perpetrator, DNA samples from the entire male population, more than 4,000 aged from 17 to 34, of the town were collected. They all were compared to semen samples from the crime. A friend of Colin Pitchfork was heard saying that he had given his sample to the police claiming to be Colin. Colin Pitchfork was arrested in 1987 and it was found that his DNA profile matched the semen samples from the murder. Because of this case, DNA databases were developed. There is the national (FBI) and international databases as well as the European countries (ENFSI: European Network of Forensic Science Institutes). These searchable databases are used to match crime scene DNA profiles to those already in a database.
The Mother of Forensic Science
Frances Glessner Lee, known as the mother of forensic science, was instrumental in the development of forensic science in the US. She lobbied to have coroners replaced by medical professionals, endowed the Harvard Associates in Police Science, and conducted many seminars to educate homicide investigators. She also created the Nutshell Studies of Unexplained Death, intricate crime scene dioramas used to train investigators, which are still in use today. Hans Gross applied scientific methods to crime scenes and was responsible for the birth of criminalistics. His 1893 Handbook for Coroners, police officials, military policemen combined in one system fields of knowledge that had not been previously integrated, such as psychology and physical science, and which could be successfully used against crime. Gross adapted some fields to the needs of criminal investigation, such as crime scene photography. He went on to found the Institute of Criminalistics in 1912, as part of the University of Graz' Law School. This Institute was followed by many similar institutes all over the world. In 1909, Archibald Reiss founded the Institut de police scientifique of the University of Lausanne (UNIL), the first school of forensic science in the world. Dr. Edmond Locard, became known as the Sherlock Holmes of France. He formulated the basic principle of forensic science: Every contact leaves a trace, which became known as Locard's exchange principle. In 1910, he founded what may have been the first criminal laboratory in the world, after persuading the Police Department of Lyon to give him two attic rooms and two assistants. Symbolic of the newfound prestige of forensics and the use of reasoning in detective work was the popularity of the fictional character Sherlock Holmes, written by Arthur Conan Doyle in the late 19th century. He remains a great inspiration for forensic science, especially for the way his acute study of a crime scene yielded small clues as to the precise sequence of events. He made great use of trace evidence such as shoe and tire impressions, as well as fingerprints, ballistics and handwriting analysis, now known as questioned document examination. Such evidence is used to test theories conceived by the police, for example, or by the investigator himself. All of the techniques advocated by Holmes later became reality, but were generally in their infancy at the time Conan Doyle was writing. In many of his reported cases, Holmes frequently complains of the way the crime scene has been contaminated by others, especially by the police, emphasising the critical importance of maintaining its integrity, a now well-known feature of crime scene examination.
The Modern Controversies
Some forensic techniques, believed to be scientifically sound at the time they were used, have turned out later to have much less scientific merit or none. Comparative bullet-lead analysis was used by the FBI for over four decades, starting with the John F. Kennedy assassination in 1963. The theory was that each batch of ammunition possessed a chemical makeup so distinct that a bullet could be traced back to a particular batch or even a specific box. Internal studies and an outside study by the National Academy of Sciences found that the technique was unreliable due to improper interpretation, and the FBI abandoned the test in 2005. Forensic dentistry has come under fire: in at least three cases bite-mark evidence has been used to convict people of murder who were later freed by DNA evidence. A 1999 study by a member of the American Board of Forensic Odontology found a 63 percent rate of false identifications. The National Institute of Standards and Technology has reviewed the scientific foundations of bite-mark analysis used in forensic science. The National Academies of Sciences, Engineering, and Medicine conducted research to address the issues of reliability, accuracy, and reliability of bitemark analysis, where they concluded that there is a lack of sufficient scientific foundation to support the data. Yet the technique is still legal to use in court as evidence. In the US, on the 25th of June 2009, the Supreme Court issued a 5-to-4 decision in Melendez-Diaz v. Massachusetts stating that crime laboratory reports may not be used against criminal defendants at trial unless the analysts responsible for creating them give testimony and subject themselves to cross-examination. Writing for the majority, Justice Antonin Scalia referred to the National Research Council report in his assertion that Forensic evidence is not uniquely immune from the risk of manipulation. In the US, another area of forensic science that has come under question in recent years is the lack of laws requiring the accreditation of forensic labs. Some states require accreditation, but some states do not. Because of this, many labs have been caught performing very poor work resulting in false convictions or acquittals. For example, it was discovered after an audit of the Houston Police Department in 2002 that the lab had fabricated evidence which led George Rodriguez being convicted of raping a fourteen-year-old girl. The former director of the lab, when asked, said that the total number of cases that could have been contaminated by improper work could be in the range of 5,000 to 10,000. The Innocence Project database of DNA exonerations shows that many wrongful convictions contained forensic science errors. According to the Innocence project and the US Department of Justice, forensic science has contributed to about 39 percent to 46 percent of wrongful convictions.
The Future of Evidence
In the past decade, documenting forensics scenes has become more efficient. Forensic scientists have started using laser scanners, drones and photogrammetry to obtain 3D point clouds of accidents or crime scenes. Reconstruction of an accident scene on a highway using drones involves data acquisition time of only 10, 20 minutes and can be performed without shutting down traffic. The results are not just accurate, in centimeters, for measurement to be presented in court but also easy to digitally preserve in the long term. Forensic science has been fostered by a number of national and international forensic science learned bodies including the American Academy of Forensic Sciences (founded 1948), publishers of the Journal of Forensic Sciences; the Canadian Society of Forensic Science (founded 1953), publishers of the Journal of the Canadian Society of Forensic Science; the Chartered Society of Forensic Sciences, (founded 1959), then known as the Forensic Science Society, publisher of Science & Justice; the British Academy of Forensic Sciences (founded 1960), publishers of Medicine, Science and the Law; the Australian Academy of Forensic Sciences (founded 1967), publishers of the Australian Journal of Forensic Sciences; and the European Network of Forensic Science Institutes (founded 1995). As of 2025, there are currently an estimated 18,500 forensic science technicians in the United States. The International Committee of the Red Cross (ICRC) uses forensic science for humanitarian purposes to clarify the fate of missing persons after armed conflict, disasters or migration, and is one of the services related to Restoring Family Links and Missing Persons. Knowing what has happened to a missing relative can often make it easier to proceed with the grieving process and move on with life for families of missing persons. Forensic science is used by various other organizations to clarify the fate and whereabouts of persons who have gone missing. Examples include the NGO Argentine Forensic Anthropology Team, working to clarify the fate of people who disappeared during the period of the 1976, 1983 military dictatorship. The International Commission on Missing Persons (ICMP) used forensic science to find missing persons, for example after the conflicts in the Balkans. Recognising the role of forensic science for humanitarian purposes, as well as the importance of forensic investigations in fulfilling the state's responsibilities to investigate human rights violations, a group of experts in the late-1980s devised a UN Manual on the Prevention and Investigation of Extra-Legal, Arbitrary and Summary Executions, which became known as the Minnesota Protocol. This document was revised and re-published by the Office of the High Commissioner for Human Rights in 2016.