Introduction
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Welcome to the amazing, wonderful, and magical world of forensic science. It's an ever exciting and changing field - new technology is popping up faster than we can keep track! But in a way that's good news, because new types of crimes are popping up everywhere too. In this class we will discuss some of the basics in forensic science, learn how the field developed, and investigate some of the techniques used.
The Basics and Some Background
First things first - what is forensic science? Forensic science is the application of knowledge and technology of science to civil and criminal laws, which are enforced by police agencies in a criminal justice system. Science can't offer final solutions that completely eradicate crime, but it does play an important role in discovering events that have occurred at a crime in an accurate and objective way.
Forensic science, also known as criminalistics, was first originated by individuals who developed techniques to identify and compare physical evidence and to those who recognized the need to meld these principles with the justice system. Even to this day, many people believe that Sir Arthur Conan Doyle had an enormous impact on forensics, by popularizing scientific methods in his crime novels of Sherlock Holmes. He was one of the first to apply the principles of serology (blood evidence), fingerprinting, weapon identification and questioned document examination - and this was done long before these practices were recognized and used in real investigations.
But there were also many others who contributed to forensic science in huge ways:
Mathieu Orfila (1787-1853) - Orfila is considered the father of forensic toxicology. He was born in Spain, but became a renowned medicine teacher in France. In 1814 he published the first treatise on the detection of poisons and their effects on animals, which led to poisons that were being used in humans.
Alphonse Bertillon (1853-1914) - Bertillon devised the first system used to identify a person. In 1879 he developed the science of anthropometry - a systematic procedure in which a series of body measurements are used as a means of distinguishing an individual from another. For two decades it was considered one of the most accurate methods for personal identification, but it was eventually replaced by fingerprinting in the 1900's. But for his efforts, Bertillon is known as the father of criminal identification.
Francis Galton (1822-1911) - Galton made the first real study of fingerprints and developed the first methodology for classifying them for filing. He published a book Finger Prints in 1892 which contained the first statistical proof supporting the uniqueness of his method of identification. He later on went on to describe the basic principles that form the current system of fingerprint identification.
Leone Lattes (1887-1954) - While in 1901 Dr. Karl Landsteiner discovered that blood can be divided into different categories (A, B, AB, and O), it was Lattes that was intrigued and thought that these groupings could be used for identification purposes. He devised a procedure which determined the blood group of a dried bloodstain, so that it could be checked against potential suspects.
Albert Osborn (1858-1946) - Osborn developed the principles of document examination and was responsible for the acceptance of documents as scientific evidence by the courts. In 1910 he wrote Questioned Documents, which was the first significant text in this field and is still considered a primary reference for document examiners today.
Edmond Locard (1877-1966) - Locard had
a formal education in medicine and law, and in 1910 he persuaded the Lyons
police department to give him two attic rooms and two
Locard believed that when a person comes into contact with another object object/person, a cross-transfer will occur. This became known as Locard's Exchange Principle, which is formally defined as "whenever two objects come into contact with one another, there is an exchange of materials between them". Using this principle, it's theorized that every criminal can be connected to a crime by dust particles carried from the crime scene.
Services of the Crime Laboratory
I don't want to venture into how laboratories are set up, because it's different for each country, and the different laws will affect the labs and what they do differently. But below are some of the basic and optional services that are commonly provided by a crime scene laboratory.
Physical Science Unit - staffed by criminalists who are experts in chemical tests and modern instrumentation to examine items as diverse as drugs, glass, paint, explosives and soil. In a lab that has a large staff this unit can be broken down into smaller task forces.
Biology Unit - this unit is staffed with biologists and biochemists who work to identify and perform DNA profiling on bloodstains, body fluids, compare hairs/fibers and identify botanical materials like wood and plants.
Firearms Unit - these experts examine firearms, discharged bullet, cartridge cases, shotgun shells and ammunition. Garments and other objects that might have been close a fired gun will also be looked at for residues.
Document Examination Unit - this unit studies handwriting and typewriting on questioned documents to determine it's authenticity and source. Other responsibilities can include analyzing paper, ink, indented writings (term for visible depressions that appear on a sheet of paper underneath the one originally written on), obliterations, erasures, and burned documents.
Photography Unit - the photography unit examines and records the physical evidence from a crime scene. The procedures used may require use of highly specialized photographic techniques such as digital imaging, infrared, ultraviolet and x-ray photography, so that invisible evidence can be seen by the naked eye. This unit will also prepare photos for courtroom presentations.
Toxicology Unit - toxicology will investigate for poisons and drugs in body fluids and organs after a crime. This unit often works closely with the medical examiner's or coroner's office.
Latent Fingerprint Unit - this unit processes and examines for latent (invisible) fingerprints when they are submitted with other lab examinations.
Polygraph Unit - the polygraph, otherwise known as a lie detector, is more of a tool for a criminal investigator, rather than forensic scientist. But during the years most police agencies have incorporated this unit into the laboratory's administrative structure. It's functions are handled by people trained in the techniques of criminal investigation and interrogation.
Voiceprint Analysis Unit - when a case involves telephoned threats, tape-recorded messages, or similar, investigators often use the skills of a voiceprint analysis unit to match the voice of a suspect. They use a sound spectrograph which transforms speech into a visual display. The validity of this technique, rests on the premise that sound patterns are unique to the individual.
Other Forensic Science Services
When discussing forensic science, most people think of the units listed above. But there are many different services that are offered. Most of these additional services are not through the laboratories, but are available to law enforcement. They are very important aids in criminal investigation and the individuals involved have highly specialized skills.
Forensic Pathology - this area involves a sudden, unnatural, unexplained or violent deaths. A forensic pathologist tries to answer the questions, "who is the victim?", "what injuries are present?", "when did the injuries occur and how were they produced?". The pathologist, also referred to as a coroner or a medical examiner, will perform an autopsy in order to answer these questions and establish the cause of death.
Forensic Anthropology - this service is concerned with identifying and examining the skeletal remains. Bones are incredibly durable and undergo a very slow breakdown process, and because of this resistance, the bones can provide a multitude of individual characteristics such as a person's gender, approximate age, race and any skeletal injuries. Forensic anthropologists also assist in creating facial reconstructions so that a composite of the victim can be made in an attempt to identify them.
Forensic Entomology - entomology is the study of insects and their relation to a criminal investigation. This practice is often used to estimate the time of death when circumstances surrounding the crime are unknown. Entomologists know how long it takes for each species of bug to "arrive at the scene", and can work their way backwards to figure out the time of death. (We will be covering this more in depth later on this term).
Forensic Psychology - this is another specialized area where the relationship between human behaviour and legal proceedings are examined. Forensic psychiatrists are often retained for civil and criminal lawsuits. In civil cases, they will make decisions about whether people are competent to prepare wills, settle on property, or refuse medical treatment. In criminal cases they will evaluated behavioural disorders, determine if people are competent to stand trial, and aid in the selection of the jury. Forensic psychologists will also examine behavioural patterns in crime and criminals to help in developing a suspect's profile. (This area is a personal favourite of mine, as it's what I'm studying in school - so we will definitely be covering this again later in the term!)
Forensic Odontology - when a body is not recognizable using normal means, police will often turn to odontologists to gain an identification using dental records. Because teeth are composed of enamel - the hardest substance in the body, the teeth can outlast all other tissues and organs as decomposition begins. The alignment, characteristics and overall structure of teeth are very unique to the individual and are a great tool for identification. Forensic odontologists can use dental records, dental x-rays or even just a photograph of a person's smile to compare to a victim. Another application of odontology is bite mark analysis. If a bite mark is left as evidence, an odontologist can compare it to a suspect.
Forensic Engineering - this unit is concerned with failure analysis, accident reconstruction and the causes/origins of fires and explosions. They will try to answer the questions "how did an accident or structural failure occur?", "were the parties involved responsible?". Accident scenes are examined, photographs looked over and any sort of mechanical object is inspected.
Forensic Computer and Digital Analysis - this is one of the fastest growing fields in forensics right now. It involves identification, collection, preservation and examination of information from computers and other digital devices, such as cell phones! Work normally involves the recovery of deleted or overwritten data from a computer's hard drive and the tracking of hacking activities. |
assistants
and he started the first police laboratory. In his early work the only
instruments he had were a microscope and a rudimentary spectrometer. But that
was overcome, and from these beginnings, Locard's research became known
throughout the world by forensic investigators. He became the founder of the
Institute of Criminalistics at the University of Lyons. 
Case Study
When a case is submitted, rarely does it fall into just one field. It's a huge, joint, and collaborative effort between all of the units. For example, when the letter below was sent to a US senator, it went to numerous fields to be analyzed. Picture and some captions from Criminalistics by Richard Saferstein.
