Forensic chemist role in Forensic Police Laboratories
"The forensic sciences refer to a group of subspecialties in science and medicine that apply their principles and methods to legal questions of a criminal or civil nature" (Nash and Faraino 1999, p.59).
Toxicology is the study of substances that are dangerous to human beings. Toxicologists have the duty of detecting and identifying the presence of drugs and poisons in fluids, tissues and organs. Its a subsection of pharmacology, one of the medical sciences. There are two central groups of toxicologists, those who study environmental toxins especially their effects on humans, and those who work in forensic toxicology. Forensic toxicology is the application of the science of pharmacology to legal cases.
A toxin is any material exerting a life threatening effect upon a living organism. Poisons are a subgroup of toxins. Toxic materials exist in many forms, and may be ingested, inhaled, or absorbed through the skin. Poisons usually enter the body in a single massive dose, or accumulate to a massive dose over time. Toxins work in minute quantities or low levels, requiring precision analytical instruments for detection.
Various toxins have medicinal value, but many produce irreversible damage. Certain toxins contain antidotes and others do not. Poisons can be Treated by quick medication, and most organ injury may be repairable. Whereas poisons are somewhat easily identifiable by their symptoms, many toxins tend to disguise or mask themselves.
For example, lead is a toxin, the toxicity of which comes from its capability to mimic other biologically significant metals, such as calcium, iron and zinc which act as cofactors in many natural physically enzymatic reactions. The most ordinary elements which fall into the class of poisons are arsenic, antimony, mercury, and thallium (Emsley 2005).
A forensic chemist is a qualified chemist who analyzes evidence that is brought in from crime scenes and reaches a conclusion based on tests run on that sample of evidence.
Forensic chemists rarely conduct any investigative work; they supervise the evidence collected from the crime scene.
Specialized forensic analysts may also be involved in identifying unsafe resources used in the commission of a crime or a threat of danger. These investigators may identify various types of toxins, fuels and bomb materials that are collected as evidence.
The single most crucial aspect of all forensic chemistry is maintaining the chain of custody. Chain of custody refers to the time course in which evidence was handled and includes every person who handled the evidence. It is imperative that evidence be handled by the lowest number of persons required to complete the forensic analysis. An ideal chain of custody is one that involves two individuals, one person who collects and delivers the evidence, and one person who analyzes the evidence. All persons in the chain of custody must be prepared to testify in court to validate the integrity of the evidence. If the chain of custody is broken in any way, the evidence will be excluded from court testimony, which often results in the dropping of criminal charges against the defendant.
Forensic toxicologists who work in crime laboratories have a splendid deal of training and experience in analysis and understanding of alcohol and illegal drug concentrations. They can determine the suitability and scientific certainty of the tests used for alcohol and drug testing. Not all tests are equal and not all meet forensic criteria of scientific certainty. The crime lab forensic toxicologist will be familiar with Kelly-Frye and Daubert requirements.
The forensic toxicologist can estimate how much drug or alcohol is in the person's body from blood or breath levels. He may be able to estimate the blood levels at the time of the incident, how long the drug would last in the blood and the period when the person took the drug. Given a drinking history or hypothetical of drinking history, he can tell what the blood alcohol levels would be for the life-time of the alcohol in that person. Given when a drug was taken, he can estimate when the peak effect Happens
Toxicology is the study of substances that are dangerous to human beings. Toxicologists have the duty of detecting and identifying the presence of drugs and poisons in fluids, tissues and organs. Its a subsection of pharmacology, one of the medical sciences. There are two central groups of toxicologists, those who study environmental toxins especially their effects on humans, and those who work in forensic toxicology. Forensic toxicology is the application of the science of pharmacology to legal cases.
A toxin is any material exerting a life threatening effect upon a living organism. Poisons are a subgroup of toxins. Toxic materials exist in many forms, and may be ingested, inhaled, or absorbed through the skin. Poisons usually enter the body in a single massive dose, or accumulate to a massive dose over time. Toxins work in minute quantities or low levels, requiring precision analytical instruments for detection.
Various toxins have medicinal value, but many produce irreversible damage. Certain toxins contain antidotes and others do not. Poisons can be Treated by quick medication, and most organ injury may be repairable. Whereas poisons are somewhat easily identifiable by their symptoms, many toxins tend to disguise or mask themselves.
For example, lead is a toxin, the toxicity of which comes from its capability to mimic other biologically significant metals, such as calcium, iron and zinc which act as cofactors in many natural physically enzymatic reactions. The most ordinary elements which fall into the class of poisons are arsenic, antimony, mercury, and thallium (Emsley 2005).
A forensic chemist is a qualified chemist who analyzes evidence that is brought in from crime scenes and reaches a conclusion based on tests run on that sample of evidence.
Forensic chemists rarely conduct any investigative work; they supervise the evidence collected from the crime scene.
Specialized forensic analysts may also be involved in identifying unsafe resources used in the commission of a crime or a threat of danger. These investigators may identify various types of toxins, fuels and bomb materials that are collected as evidence.
The single most crucial aspect of all forensic chemistry is maintaining the chain of custody. Chain of custody refers to the time course in which evidence was handled and includes every person who handled the evidence. It is imperative that evidence be handled by the lowest number of persons required to complete the forensic analysis. An ideal chain of custody is one that involves two individuals, one person who collects and delivers the evidence, and one person who analyzes the evidence. All persons in the chain of custody must be prepared to testify in court to validate the integrity of the evidence. If the chain of custody is broken in any way, the evidence will be excluded from court testimony, which often results in the dropping of criminal charges against the defendant.
Forensic toxicologists who work in crime laboratories have a splendid deal of training and experience in analysis and understanding of alcohol and illegal drug concentrations. They can determine the suitability and scientific certainty of the tests used for alcohol and drug testing. Not all tests are equal and not all meet forensic criteria of scientific certainty. The crime lab forensic toxicologist will be familiar with Kelly-Frye and Daubert requirements.
The forensic toxicologist can estimate how much drug or alcohol is in the person's body from blood or breath levels. He may be able to estimate the blood levels at the time of the incident, how long the drug would last in the blood and the period when the person took the drug. Given a drinking history or hypothetical of drinking history, he can tell what the blood alcohol levels would be for the life-time of the alcohol in that person. Given when a drug was taken, he can estimate when the peak effect Happens
