Toxicology refers to the study of how drugs, chemicals and similar substances affect biological systems and processes. Forensic toxicology is at the intersection of science and the law. These professionals are a type of medical scientist. They examine how substances may have affected human behavior or otherwise contributed to an unlawful act.
The work that forensic toxicologists do is vital for identifying substances criminal suspects may have been under the influence of and developing sufficient evidence to convict them in court. When working, they collaborate closely with other scientists, lab technicians, forensic pathologists, homicide investigators, crime scene technicians and similar professionals to put together a case against a suspect. As the observations of the arresting officer provides the foundation for the arrest, it is the work of the toxicologist that provides strong support for the officer’s decisions and can contribute to a conviction.
Unlike crime scene investigators, forensic toxicologists do not visit crime scenes. Their work is primarily conducted in a lab. They use state-of-the-art lab equipment to analyze collected samples, which may include body fluids, tissue samples, hair, nails and any other specimen that may shed light on the substances a person has ingested as part of a criminal investigation.
There are a variety of techniques and analysis tools that a forensic toxicologist might use to analyze the evidence. These include the following:
- Gas and liquid chromatography
- Mass spectrometry
- Spectrophotometry
- Antibody-based immunoassays
These tests are used to determine which drugs or other substances are present in a sample, as well as the concentrations of those substances. Forensic toxicologists must apply their expert knowledge to interpret test results, such as by determining the timing and extent of impairment due to a person’s drug use.
After analyzing the samples and interpreting the test results, forensic toxicologists type up reports that detail their findings. Those reports are then sent to law enforcement officers and other involved professionals, such as the prosecutor assigned to the case. The toxicologist may need to provide follow-up information to law enforcement personnel if any questions remain or any new evidence becomes available for the case.
If the case goes to trial, the toxicologist can expect to be called to testify. The testimony will explore the toxicologist’s lab procedures and test result interpretations. The professional will be called upon to explain how the suspect or victim would have been impaired by the substance(s) found in the samples.