Most criminal investigations start with the assignment of a law enforcement investigator. But behind those investigators are a heavy hitting team of scientists known as forensic investigators.
Watching true crime and procedural television programs, most people probably are most familiar with pathologists and toxicologists as forensic investigators. But the 7,000-member American Academy of Forensic Sciences recognizes a total of 11 disciplines.
Here are the disciplines that officially make up the scope of forensic investigation:
Anthropology: A subfield of physical anthropology, or the study of human remains, some of which may be from crime scenes while others may come from ancient burial grounds, this type of forensic specialist is called in when bones are found but their age and circumstances are unknown. Regardless of the source of the bones, the same skeletal analysis and archaeological techniques, including excavation and the recording of evidence, are applied to determine who died, how they died and when they died. Among the individual characteristics a forensic anthropologist is able to determine are age, gender and ancestry.
Criminalistics: More commonly known as “forensic science,” this specialty is made up of scientists who study and evaluate physical evidence collected during the investigation of crimes, from burglaries and robberies to assaults and homicides. Criminalists, who are commonly referred to as “lab technicians” or crime scene investigators, are charged with linking the evidence at a scene, such as fingerprints, hair and blood, to victims and suspects. Criminalists also try to reconstruct evidence of how a crime occurred, such as determining the distance between a victim and a shooter in a firearms incident.
Digital and Multimedia Sciences: Sometimes, the evidence of a crime doesn’t involve a body and bodily fluids. The digital forensic investigator often is involved in sorting out the details of white-collar crimes, such as hacking or the recovery of lost or stolen data. These forensic specialists may be hired by government agencies or private companies on a full-time or contracted basis to conduct internal or external investigations. Those working in cyberforensics must have a knowledge of the law, policies and ethics in terms of cybersecurity and privacy; encryption algorithms; and a variety of computer servers and operating systems.
Engineering and Applied Sciences: This discipline broadly involves the investigation of performance problems and failures, such as a building or bridge collapse. This is done by collecting data and physical evidence from the catastrophe. The role of the forensic engineer is to prevent future problems and failures. From a justice standpoint, this particular type of forensic specialist may not be involved in criminal investigations as often as others, but there are times their expertise may be called for in court, especially for civil litigation.
General: Rather than being specialists in one area of crime scene reconstruction, forensic generalists rely on skills from several disciplines, including fingerprinting, DNA analysis or ballistics. Practitioners can be found in government settings, at colleges and universities, or in private practice.
Jurisprudence: Forensic science, in general, is a blend of law, science and expert opinion. This specialty mostly involves the application of science and medicine to legal problems by an expert witness in issues, such as death, rape and paternity. Medical jurisprudence may include the competence or sanity of parties in criminal and civil proceedings; assessment of injuries in suspected cases of abuse; and fitness to participate in certain activities, such as driving, motor vehicles or piloting airplanes, athletic or certain occupations.
Odontology: This specialty involves the application of dental knowledge, most often to distinguish between human and animal bite marks and for establishing the identification, age and/or gender of a human. With humans, that could be applied to victims when there are few other ways to identify who they are and to suspects who may have bitten someone during an incident under investigation. Their expertise also might be sought in civil matters involving malpractice or negligence. Odontologists also can be called in for natural disasters that result in mass deaths, such as tsunamis, hurricanes or volcanoes.
Pathology/biology: The forensic pathologist is a specialist in applying science to ascertaining a cause of death for someone who has died suddenly, unexpectedly or violently. They are medical doctors who are specially trained to collect and document evidence; perform autopsies that help determine the presence of disease, injury or poisoning; and reconstruct how injuries occurred. The forensic biologist applies his or her familiarity with plant and animal anatomy, lifespans and systems to their impacts on human events. Some may specialize in the knowledge of only one organism, while others may study entire groups of plants and animals.
Psychiatry/behavioral science: These forensic specialists apply clinical specialties, such as cognitive or social psychology, to a legal setting through the use of assessments, treatments and evaluations. As researchers, forensic psychologists study legal issues, such as the reliability of eyewitness identification or children’s memory and susceptibility to suggestion. One of the most well-known functions of a forensic psychologist is determining whether an individual meets the legal threshold of insanity. Forensic behavioral scientists study human behavior as it relates to the commission of criminal offenses, with an eye on prevention. They help determine which behaviors are warning signs for criminal activity, creating effective treatment plans for those likely to offend, and help establish sentencing that is not just punitive but beneficial to an offender.
Questioned documents: These are forensic specialists brought in to determine authenticity and origin; examine documents suspected of alteration or forgery; and analyze the composition of paper. This may be done through analysis of handwriting and typewriting, ink or surface features of a document. Techniques used include indented writing analysis, in which the imprint of writing on a top sheet of paper is examined on the sheets below it and video spectral analysis used to identify altered or counterfeit documents through the detection of watermarks, latent images or photo substitutions.
Toxicology: This forensic specialist works with coroners,medical examiners and pathologists to establish a cause of death. They rely on the use of analytical chemistry, clinical chemistry and pharmacology to investigate deaths, drug use and poisonings. The toxicologist can glean samples from a variety of crime scene evidence, including bodily tissues and fluids, pill bottles and trace residue. Toxicologists also rely on a variety of high-tech testing methodologies, including gas or liquid chromatography-mass spectrometry, or the Reinsch test or X-ray diffraction for metals detection,