Forensic scientists apply the concepts of analytical chemistry and toxicology to solve medical and legal mysteries, and they call this field forensic toxicology. Administrators or judges may use the findings of these analyses in proceedings. This field of study is constantly growing and includes areas such as death investigations, undeclared drug prescriptions, medical errors, drug overdose diagnosis and treatment, chemical/toxin exposure, aspects of behavior or human performance (such as drug-impaired driving or steroid use by athletes), and workplace drug testing. Expertise in biochemical, pharmacological, and phytochemical analysis is necessary for forensic toxicology. Forensic toxicologists work in conjunction with other experts like pathologists, medical examiners, and law enforcement officers to acquire the best results. In general, there are two subfields in forensic toxicology:
Types of Forensic Toxicology
- Post-mortem toxicology (also known as death investigation toxicology)
- Toxicology of human behavior or performance.
Post-mortem Toxicology
Post-mortem toxicology is the quantification of medications (such as antiepileptics and neuroleptics), poisons, alcohol, and other chemicals to determine how they affect a person’s demise. The chemical content in blood or any other tissue must be quantified to prove a cause-and-effect relationship. For instance, analysts use human hair analysis to provide details on the medications used and their time distribution (they adjust the results based on average hair growth). Forensic experts also use analyses of body parts tainted with paint, gunshot, drug, or body fluid remnants to connect specific people to crimes. However, errors in sample processing or testing sensitivity, post-mortem artifacts, and drug redistribution throughout the body can all have a significant impact on toxicology used in death investigations. Drugs specifically go from the blood to the liver, lungs, and brain.
Toxicology of Human Behaviour or Performance
Toxicologists study the existence, usage, or abuse of chemicals discovered in illegal trafficking and, with no proven medical benefit, a field known as behavioral or human performance toxicology. They categorize these substances into the following classes: narcotics, depressants, stimulants, hallucinogens, and anabolic steroids. Researchers take samples for these studies from living people, thereby avoiding post-mortem medication redistribution-related interferences. However, they must consider different windows for detection because of metabolism. For instance, they can detect heroin and cocaine in urine or saliva if consumed up to a week prior, whereas they can detect marijuana up to a month prior. Most drug testing uses these matrices because “the same drugs deposit in hair for months.” Long-term exposure can also be detected using this kind of sample. However, certain medications stay in the blood for long periods of time.
Analytical Approaches
The two types of analytical approaches most frequently used in forensic toxicology are immunoassays and chromatographic procedures.
Immunoassays
Biochemical tests called immunoassays employ an antigen or an antibody to detect the presence or concentration of a molecule in a solution. As a result, the producers of reagents still control the selection of immunoassays. These tests are primarily used to check urine for the presence of drugs of abuse. Still, it is important to consider any interference from other drugs or non-drug chemicals that may be present unintentionally or on purpose.
Immunoassays are typically quick and easy to run, however they contain some cross-reactivity with other compounds that can be problematic. Due to various variables, including the structural and conformational similarities of numerous medicines, which allows antibody binding to happen when several drug groups are involved; the indicator reaction employed in homogeneous immunoassays is non-specific because of the consumption of coenzyme or the suppression of enzyme activity; and the development of a high background absorbance that prevents measuring techniques from working.
Chromatographic
Chromatography is the most used technology in forensic toxicology due to its flexibility and capacity to separate and identify the most toxicologically significant substances. It is a process by which a chemical mixture carried by a liquid or gas is split into elements because of the solutes’ differential distribution as they flow around or over a stationary liquid or solid phase. Chromatography necessitates a high level of ability to keep the instrumentation functioning well and achieve trustworthy results. The various chromatography procedures differ depending on the extraction techniques, stationary phases, derivatization mechanisms, and detectors used.
What Biological Samples Are Used in Forensic Toxicology?
Some of the most common biological samples used in forensic toxicology are as follows:
- Hair
- Blood
- Saliva or Oral Fluids
- Urine
- Nails
- DNA
- Gastric Contents
- Vitreous Humor
- Post-mortem Sample
How Does Forensic Toxicology Help Attorneys?
Forensic toxicology is a vital resource and an indispensable tool for attorneys within the legal landscape. Attorneys frequently rely on forensic toxicologists for expertise, analysis, and interpretation of toxicological evidence in various legal cases. Here’s how forensic toxicology aids attorneys in their practice:
Evaluating Evidence Credibility
Attorneys consult forensic toxicologists to evaluate the credibility and validity of toxicological evidence presented by the opposing party. This ensures the evidence meets scientific standards and has been collected, stored, and analyzed correctly.
Expert Witness Testimony
Forensic toxicologists often serve as expert witnesses, providing professional opinions and expert testimony regarding toxicology findings. Their testimony can be crucial in explaining complex scientific concepts to judges and juries, aiding in understanding toxicological evidence.
Assisting in Case Strategy
Attorneys collaborate with forensic toxicologists to develop effective case strategies. Understanding the toxicological evidence allows attorneys to formulate arguments, cross-examine witnesses, and challenge opposing evidence, ultimately strengthening their case.
Reviewing Autopsy and Medical Reports
Forensic toxicologists analyze autopsy and medical reports to provide attorneys with an accurate understanding of toxicological findings. This helps attorneys determine the impact of toxic substances on their client’s case and develop appropriate legal strategies.
Challenging Prosecution Claims
Attorneys can engage forensic toxicologists to challenge the prosecution’s claims based on toxicological evidence. These experts can identify weaknesses or inconsistencies in the evidence and help build a strong defense for their clients.
Interpreting Toxicology Reports
Toxicology reports can be complex and technical. Forensic toxicologists assist attorneys in interpreting these reports, ensuring they fully understand the implications and nuances of the toxicology findings related to their case.
Establishing Cause of Death or Injury
In cases involving fatalities or injuries, forensic toxicologists play a critical role in establishing whether a toxic substance contributed to the cause of death or injury. This information is pivotal for building a strong case.
Providing Legal Opinions
Forensic toxicologists can provide attorneys with expert opinions on the admissibility and reliability of toxicological evidence, helping attorneys make informed decisions regarding the evidence’s use and relevance in court.
Navigating Legal Regulations
Forensic toxicologists assist attorneys in navigating the complex legal and regulatory landscape related to toxicology. They provide insights into relevant laws and regulations that may impact the case.
Conclusion
With its intricate analyses and precise methodologies, forensic toxicology stands as a pillar in the medico-legal process. It reveals hidden truths, bringing justice to light. As this field continues to evolve with technological advancements, it reaffirms its commitment to truth, integrity, and the pursuit of a just society. Forensic toxicology will remain an unwavering ally in the quest for justice, unraveling the enigma that shrouds many legal cases. A successful laboratory will need to strengthen this business sector since this article’s conclusion attempted to show how the field of forensic toxicology is expanding.
