The cause and manner of a death are not always evident, even after visual examination and dissection and examination under a criminological microscope. From 1800 onward, scientific investigators continually devised procedures, instruments, and technologies of visibility, to reveal what the naked eye could not see.
Chemical analysis using criminological microscopes helped detect traces of poison in the victim’s body. Microscopes made it possible to see tiny lesions, crystals, and hairs. Spectroscopic analysis of blood and other materials helped match trace elements linking the victim and the killer.
As commercially manufactured poisons became increasingly available in the 19th century, poisoning became known as a modern and disturbingly hard to detect method of killing. In response, researchers developed toxicology as a specialized field of forensic medicine, and devised specific tests for poison, most famously the 1836 Marsh Test for arsenic.
The new science of toxicology was plagued by difficulties. In the courtroom and laboratory, seemingly reliable tests were shown to be flawed. But, over time, toxicology trials led to better knowledge of the action of poisons and better methods of chemical analysis using criminological microscopes.
The Industrial Revolution introduced cheap poisons into homes, factories, and farms. To prevent accidents, poisons were sold in colorful and distinctively shaped bottles. But toxic substances were also used in widely available medical preparations, which poisoners could use to dispatch their victims.
Mid 19th century improvements enabled physicians to use microscopy in criminal investigations. The microscope made it possible to view tiny lesions, crystals, microorganisms, and the characteristics of hairs and fibers. By the mid 20th century, investigators were using microscopes to study tissues, wounds, and fluids from victims and suspects; to identify poisons in and around the victims body, to examine minute amounts of trace elements; and to link the victims body to the perpetrator and crime scene.
Spectroscopy was born in the mid 17th century, when Isaac Newton discovered that a prism divides white light into constituent colors. Subsequent researchers discovered that specific substances, subjected to flame, give off unique patterns of light that show characteristic emission bands and absorption lines when cast through a prism. By the 1870s and 1880s, spectroscopy seemed a promising new forensic technology. Further work on spectra analysis led to spectrophotometry and, more recently, mass spectrometry. In tandem with gas chromatography, mass spectrometry is now often used to identify and match organic and inorganic substances for forensic purposes.
For centuries, anatomical specimens from the bodies of crime victims have been used as teaching tools and souvenirs of interesting or important cases. These specimens demonstrate various types of traumatic wounds of the heart, kidney, and stomach. Physicians and surgeons first gained practical knowledge of death and decomposition through handling and dissecting bodies obtained for anatomical study. Over the course of the 19th and 20th centuries, the study of the decomposed body and body parts the effects of time, environment, and manner of death became a vital part of forensic science.
In cases of homicide or suspicious death in medieval England, the coroner, an appointed official who had no medical training, was required to make “a view of the body,” a legal, visual inspection. Since then, medical professionals have played an increasingly important role in making views of the body. Physicians and surgeons have developed methods of seeing into the body through autopsy and post-mortem examination—making visible what the untrained, unequipped eye cannot see.
Post-mortem dissection, or autopsy, was among the earliest scientific methods to be used in the investigation of violent or suspicious death. Autopsy remains the core practice of forensic medicine. The postmortem examiner surveys the body’s surface, opens it up with surgical instruments, removes parts for microscopic inspection and toxicological analysis, and makes a report that attempts to reconstruct the cause, manner, and mechanism of death. These clips from training films show some of the procedures of postmortem examination.
The post-mortem examiner visually surveys the body surface before opening and entering the body with the help of a scalpel and other instruments. After visual examination of the body cavities, the examiner removes parts for chemical analysis, inspection with a microscope, and other tests. Tools and tool kits specially adapted for use in autopsy first appeared in the early 19th century.
