A body was found in a small rural village. The murder weapon was determined to be a sickle. All men owning a sickle are called to the town center and instructed to lay their tools out in front of them. To the naked eye, all the sickles are clean; there was no visible evidence on any of the tools. Yet, a large mass of flies was attached to one weapon. Blood and tissue that was not yet visible was attached to the blade. The owner, besieged with guilt, “dropped to his knees and confessed.” This homicide investigation was solved in 13th Century China, the first recorded use of forensic entomology, the study of insects.
Entomologists use two methods of determining elapsed time since death. The first method is based on the predictable development of blowflies over time. This technique is used from when the first eggs lay on the remains until the first adult fly emerges from the pulpal cases and leaves the body. The second method utilized is the predictable growth of insects on a body. This method can be used within a few days of death until nothing is left but dry bones.
Subject matter experts have provided crucial intelligence and assistance to homicide investigations for centuries. Forensics scientists’ expertise is required to determine the cause of death, the time of death, blunt force injuries, stab wounds, age of the victim, and the nature of the death. Subject matter experts include forensic botanists, toxicologists, forensic pathologists, forensic entomologists, forensic anthropologists, and archaeologists.
Forensic pathologists are employed to investigate the death of a person who died suddenly and unexpectedly, or as a result of injuries. In the United States, the terms medical examiner, coroner, and forensic pathologist are interchangeable. Forensic pathologists are medical doctors who have received advanced training in recognizing and interpreting diseases and injuries to the human body.
For centuries, poison was the favorite method to kill another person. Poison leaves no cuts, no wounds, or bloodstains. Socrates was sentenced to death when he was ordered to drink hemlock after being found guilty of corrupting Athens’ youth. Toxicology is the study of poisons. Forensic toxicology is utilized in postmortem drug testing to establish whether or not drugs were the cause or contributing factor in the death. Since the emergence of forensic toxicology testing, the use of poison in homicide matters has decreased to six percent of all murders.
Deborah Blum’s book, The Poisoner’s Handbook: Murder and The Birth of Forensic Medicine in Jazz Age New York City attributed the success of forensic toxicology to Charles Norris. Norris, New York City’s first medical examiner, stated “There would be no good criminal justice unless marched hand in hand with good science.” Norris’ office was instrumental in identifying why female employees of the United States Radium Corporation began to suffer from anemia, bone fractures, and a condition known as radium jaw. The females’ contracted radiation poisoning when they licked the paintbrushes they used to paint military watch faces. The paint used on the watch faces contained deadly amounts of radium. When the employees became sick, the company attempted to discredit the females and attributed their illness to sexually transmitted diseases. Five of the employees filed suit, which later established legal precedents and regulations governing labor safety standards.
Forensic toxicology testing was instrumental in identifying ricin as the poison that killed Bulgarian writer Georgi Markov. Markov, a harsh critic of the Bulgarian government, escaped to England in 1971. As Markov was walking across a bridge, an unidentified male struck Markow in his leg, leaving a small puncture wound. Four days later Markov was dead. Ricin leaves no trace in the body; however, death comes from an electrolyte imbalance. The scientist injected a pig with the same amount of Ricin injected into Markov’s leg resulting in the pig's death within twenty-four hours.
Forensic botany is the application of plant science to legal questions. Although underused because many investigators underestimate the value of plant evidence, plant evidence has been used in criminal investigations.
The first use of botanical evidence was in the 1932 Lindbergh kidnapping case. Charles Lindbergh, Jr., the son of aviator Charles Lindbergh, was kidnapped from the Lindberg home and later murder despite the payment of a $50,000.00 ransom. Located in the Lindbergh home was a make shift ladder used in the kidnapping. The wood in this ladder was matched with attic board from suspect Bruno Hauptman’s home. This evidence, with additional forensics evidence, linked Hauptman to the crime and lead to Hauptman’s conviction.
Forensic botany is subdivided into several subspecialties including plant anatomy, which is the study of cellular features; plant species identification, which studies the process of matching a plant to a known category; and poll plant species identification, which helps determine a sample’s geographic origin and provides links between a crime scene and suspects, tests alibis, and assists in the identification of the primary or secondary crime scene sites.
For example, seed evidence linked Kevin Neal to a wooded area where his two stepchildren, ages 11 and 4, were found murdered in 1997 in Ohio. Seeds found on Neal’s clothing were found at the gravesite, not in Neal’s yard as he claimed. Neal was convicted of the two murders.
A developing forensic science discipline is the collection of soil samples. Soil collection as well as the collection of plant and trace evidence is based on Locard’s Exchange principle. Locard’s principle states that when two objects come into physical contact there is a mutual exchange of trace evidence between them.
On September 18, 2000, a husband arrived at his home in Australia to find his wife, mother-in-law, son, and the family car missing. Earlier in the day, neighbors reported a disturbance at the home. The next day the car was located 200 kilometers away from the family home. Recovered from the car’s trunk were a pine post, a bloodstained shovel caked with pinkish blood soil, clothing, boots, and other evidentiary items. The son was arrested and charged with murder although the bodies had not been found. The presence of the shovel with the bloodstain in the soil indicated the victims might have been buried. However, the suspect was not talking. The scientists analyzed and compared the soil samples to ascertain soil source in a geographic region to assist the investigators with their search for the bodies. The analysis of the soil indicated the soil originated in a mine or quarry location. A short distance from the victims‘ home was a quarry. The police conducted daily inspections at the quarry, which lead to the discovery of the victims’ bodies three weeks after their disappearance. Based on the overwhelming evidence, the son confessed to murdering his mother and grandmother and was sentenced to life in prison.
In this presentation, we have discussed the role of forensic pathology, toxicology, botany, entomology, and soil experts. We have also discussed how these experts assist investigators with solving crimes.