Forensics Collection and Analysis of Evidence - Essay Example

Forensics Collection and analysis of evidence - Toxicology Forensic toxicology is a branch of forensic medicine, which involves the collection and analysis of specimen for criminal investigations. This is very vital since it helps in establishing whether there was use of a drug or poison in causing death. It also helps in establishing the specific kind of poison or drug taken and the quantity. This paper delves into forensic toxicology. It first provides a brief history of forensic toxicology, the main specimens used, the collection and analysis, interpretation of evidence and challenges facing the viability of whole process. Introduction Forensic toxicology is the use of toxicology to assist medico-legal analyses and investigations of death and poisoning. In a wider sense, it also extends to comprise workplace drug testing as well as investigating the drivers who are driving under the influence of drugs and alcohol (Penders & Verstraete, 286). According to Levine, Forensic toxicology is the use of toxicology for the functions of the law. Under the broad forensic toxicology, there are three major sub-fields. These include “postmortem forensic toxicology, human performance toxicology and forensic drug testing.” However, since the major aim of practicing forensic toxicology is to investigate a fatality, most analysts conduct the examination and analyses on specimens from dead people (3). Riviello adds that forensic toxicology centers on medicinal features of destructive impacts of chemical toxins. In addition, pathologists are the ones who collect most of the specimens used for forensic toxicology or postmortem analysis. Conversely, medical practitioners and other clinical officers might also be very useful in forensic toxicology. The main reason for this assertion is the fact that they are frequently the first people to observe, detect and gather samples from patients who might be subject of lawful investigation. Moreover, there should be careful and proper handling of forensic specimens from collection to analysis to avoid getting inappropriate or deceiving results (36). History and importance of forensic toxicology The methodical study of forensic toxicology started during the late eighteenth century. It emanated as a segment of forensic medicine primarily dealing with the issue of establishing purposeful poisoning in criminal investigations. However, the major challenge was that it was frequently very hard to differentiate signs emanating from numerous common poisonous plants with those of particular diseases. Due to this, most medical practitioners and physicians concurred that improved knowledge of the chemical features and physiological effects of toxins would assist diagnosis and management in addition to the search for evidence (Coley, 409). In 1814, M.J.B. Orfila, the chair of the legal medicine department at the Sarbonne in France, made the initial effort to analytically study and classify poisons. Moreover, he was the first researcher to establish that for poisons to portray their poisonous effects, they must be absorbed in the blood. In 1951, Jean Servais Stas initiated the first successful approach of extracting alkaloids from biological samples (Levine, 3). In the criminal courts medical specialists, presented proof founded on clinical and pathological examinations, and deduced in terms of modern ideas of the physiological impacts of drugs and poisons (Coley, 410). The most apparent significance of postmortem forensic toxicologic examinations lies in supposed drug intoxication cases not readily detected at autopsy. In the case of intravenous drug fatalities, a fresh injection site might be observable, and numerous unabsorbed tablet pieces in the stomach might infer oral intoxications. Forensic toxicology is also in investigation of deaths other than drug intoxications, for instance homicides and unintended deaths. Various medical inspector or coroner’s offices regularly carry out drug examinations for all homicides as many homicides are drug connected and the abuse of drugs might present an intention for homicide (Levine, 4). Riviello argues that the toxicologic examination is essential in establishing whether there was use of a drug as the cause of a patient’s morbidity or death. In addition, forensic toxicology is useful in establishing the particular drug that caused the death, the quantity taken and the time taken (37). Moreover, forensic toxicology might also be useful in the investigation of deaths due to natural causes. For example, deaths from convulsions happen with and without anatomic results. Furthermore, successful quantification of blood levels of anti-convulsant drugs might permit the assessor to establish whether the deceased died of under-medication or noncompliance (Levine, 4). Collection, storage and analysis of specimen in forensic toxicology The conditions surrounding the case frequently pre-establish the selection and collection of biologic specimens. The most ordinary samples collected for forensic toxicology are blood and urine. This is due to their ease of collection and accessibility of testing in a well-timed approach in the hospital setting. For blood sample collection and storage, the examiners regularly use glass containers (Riviello, 37). Richardson adds that urine is generally sufficient, if the volume collected is enough to permit the performing of any essential confirmatory tests. Moreover, the person collecting the urine samples should put it into two separate containers each closed and labeled. In this regard, the examiner only uses one of the specimens for analysis and save the other container in case, a third party asks for independent analysis (21). In addition to this, it is vital to preserve all blood samples presented for biochemical or hematological investigation to facilitate performing of confirmatory tests when the urine volume is inadequate. A blood sample will often permit quantification of the poison in support of the clinical conclusions (22). The analysis of specimen for forensic toxicology starts with the identification of the drugs or toxins involved followed by the quantification of the obtained outcomes. For forensic toxicology, there are several toxicology laboratory tests. These include “spot tests, spectrochemical tests, immunoassays on-site drug tests and gas-chromatography tests.” Most clinical laboratories carry out a fast screening test for instance an immunoassay, followed by a more thorough and labor-exhaustive analysis using gas chromatography (Riviello, 38). When using blood and urine as specimens, the examiners use at least 40mL blood and all the obtained urine for analysis. The uoride concentration in the uoride tubes used medically for gathering blood for glucose establishing is inadequate to hamper the alterations in ethanol concentrations that arise in autopsy samples after sampling (Richardson, 22). In addition, the analysts should carry out the forensic analysis in a good manner, which would also meet the required standards of any toxicology examination. This is because, when they use non-validated methods or samples, there would be the risk of getting fake positives or fake negatives (Penders & Verstraete, 286). Interpretation of results and challenges that occur Riviello states that interpretation of forensic toxicology results might prove difficult in some occasions. This can happen because patients might have positive laboratory results with negligible or no symptoms of poisoning. This could be because of drug tolerance or the extended existence of the drug’s metabolite (39). Richardson indicates that the interpretation of the urine drug screen, from whatsoever source, is comparatively simple provided one has the applicable information available. For sufficient interpretation, consistent and advanced reference ranges for remedial and toxic rates are necessary in addition to the proper information (33). Patients who die in hospital following an extended period might not essentially be free from ethanol at autopsy. Moreover, different persons react differently to drugs from time to time and from other persons due to various personal aspects (35). Peovsky and co-authors present two cases that revealed evidence of intoxication. In the first case, a 51-year-old man crumpled upon severe myocardian infarction. He had a history of high blood pressure and he was constantly taking medication to manage it. After hospitalization, the emergency offered him cardiopulmonary resuscitation. However, the patient passed on 30 minutes following the commencement of rigorous resuscitation. At autopsy, he had severe coronary arteriosclerosis and there was thrombus in the left coronary artery. In the second case, a 23-year-old man found dead in his bed, had his head concealed in a black plastic bag fixed around his neck. After examination, there was proof of latest abuse of ethyl alcohol. The external and internal autopsy examinations verified the suffocation in unbreathable propan-butan condition (3). However, Richardson presents several challenges that occur while retrieving evidence from specimen collection to analysis. For the analysis of unstable toxins from intensely poisoned patients, plastic tubes are substandard. This is mainly because solvents in the specimen will dissolve into the plastic wall of the container or into the rubber of a glass pipe. In addition, post-mortem samples taken from a patient who has died in hospital some days following a self-poisoning incident are will probably be negative, depending upon the drug entailed (23). Conclusion Forensic toxicology is becoming very popular among criminal investigations as well as medical departments. It is very important and of great interest since it helps in the establishment of evidence of intoxication. The main biological specimens often used for analysis are blood and urine. However, there are various challenges that occur, which might lead to misleading results. In order, to curb the challenges experienced during collection and analysis, there should be careful documentation of every step in the process of collection, transport, receipt, analysis and storage of forensic specimens. Works Cited Coley, Noel. “Alfred Swaine Taylor (1806-1880): Forensic Toxicologist.” Medical History 35 (1991): 409-427. Print. Levine, Barry. Principles of forensic toxicology. New York: American Association for Clinical Chemistry, 2003. Print. Penders, Joris & Verstraete, Alain. “Laboratory guidelines and standards in clinical and forensic toxicology.” Accreditation and Quality Assurance 11 (2006): 284-290. Print. Peovsky, P. et al. Remedy in Forensic and Legal Medicine Toxicology. 2003. Web. Richardson, T. “Pitfalls in forensic toxicology.” Annual Clinical Biochemistry 37 (2000): 20-44. Print. Riviello, Ralph. Manual of Forensic Emergency Medicine: A Guide for Clinicians. London: Jones & Bartlett Learning, 2010. Print. Read More