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Chemical analysis has an important role in law enforcement and forensics. This
methodology is known as Forensic chemistry. The purity of a material could be
detected using spectroscopy techniques and this could be major analysis in
approving results. To detect evidences and in the field of narcotics, forensic
chemistry play an important role.
Illegal drugs are major target of forensic chemistry experts. These drugs are
threat to society and global market, where in forensic science; the forensic
chemistry is widely used to explore these crimes. There are forensic analytical
techniques, where forensic chemistry is used to estimate age of an unknown
human body will be estimated. Use of chemicals in revealing unknown facts of
evidence is forensic chemistry.
Toxicology is the study of the adverse effects of drugs and chemicals on biological systems. It is understood as that branch of science which deals with poisons, and a poison can be defined as any substance that causes a harmful effect when administered, either by accident or design, to a living organism.^1 Toxicology does embrace the study of deleterious effects of substance exposure not only to the human body but also to the environment and all other organisms existing in the environment.^2 Whereas, Forensic toxicology, is the use of toxicology and other disciplines such as analytical chemistry, pharmacology and clinical chemistry to cases and issues where those adverse effects have administrative or medico‐ legal consequences, and where the results are likely to be used in court.^3 It is a thoroughly modern science, based on published and widely accepted scientific methods and practices, for both analysis of drugs in biological materials, and interpretation of those results. Many of the methods it employs have been derived from innovations in clinical medicine and academic laboratories throughout the world.^4 The application of this knowledge of drug presence (through forensic toxicology) in tissues is to meet the varied needs of the law. The interpretation of effects of drugs and their duration of action for the purpose of a medico-legal process is best referred to as forensic pharmacology, although there is overlap between these two scientific disciplines.^5 The first comprehensive work on Forensic Toxicology was published in 1813 by Mathieu Orfila. He was a respected Spanish chemist and the physician who is often given the distinction of “Father of Toxicology.” His work emphasized the need for adequate proof of identification and the need for quality assurance. It also recognized the application of forensic toxicology in pharmaceutical, clinical, industrial and environmental fields. The
primary concern for forensic toxicology is not the legal outcome of the toxicological investigation, but rather the technology and techniques for obtaining and interpreting the results. Forensic toxicology is governed through various professional certifying and accrediting boards in various places such as- The American Board of Forensic Toxicology (ABFT) - and promotes professional development and education through major professional organizations, the Society of Forensic Toxicologists (SOFT), the American Academy of Forensic Sciences (AAFS), and international organizations such as The International Association of Forensic Toxicologists (TIAFT). As a matter of fact we know that with the advent of 21st century, the scope of a forensic toxicology service has technically and intellectually become very demanding. Even though the short-comings of forensic toxicology persists in some spheres, still its role in delivering the justice and solving criminal cases has been highly appreciated and relied upon. Yet after the limitations, the court and society at large depends on the findings of the forensic examination and reports. The growth of forensic studies in field of toxicology is witnessed because as the society advances and becomes more complex, the crime presents itself in different forms. This correspondingly necessitates the employment of modern scientific techniques in investigation. This need of the society is taken care by the field of forensic toxicology. Conte, Raffaele. (2020). Importance of Forensic Toxicology: The Case Study of AMES. Newsletter n 16. Retrieved from https://www.researchgate.net/publication/344189782_Importance_of_Forensi c_Toxicology_The_Case_Study_of_AMES
This article is from Raffaele Conte
routinely collected, and the extent to which this evidence is submitted to and examined in forensic crime laboratories. There is even less research that describes the role and impact of such evidence on criminal justice outcomes. While the current study shows that forensic evidence can affect case processing decisions, it is not uniform across all crimes and all evidence types; the effects of evidence vary depending upon criminal offense, variety of forensic evidence, the criminal decision level, and other characteristics of the case. The current study attempted to fill this gap in knowledge by examining the role and impact of forensic evidence on five felony crimes across five jurisdictions. Given the varied nature of the criminal offenses, as well as contextual differences across study sites, the project reached the following conclusions: 1. The study data revealed that the collection of forensic evidence from crime scenes (and victims) was very extensive in homicides and, to a lesser extent, rapes; it was much more limited for assault, burglary and robbery offenses. 2. With the exception of homicides (89%), few of the reported crime incidents had forensic evidence that was submitted to crime laboratories. While the rate of submission of evidence for rape was 32%, submission rates in assaults, burglaries and robberies were under 15% of reported offenses. 3. With the exception of homicides (81%), the overall percent of reported crime incidents that had physical evidence examined in crime labs was low. Less than 20% of rape cases and less than 10% of assault, burglary and robbery incidents had lab examined evidence. Of evidence submitted to labs, however, rates of examination, with the exception of rape cases (58%), exceeded 70%. Consequently, it is clear that criminal justice officials external to the laboratory screen much of the forensic evidence and have a major influence on evidence examination priorities and practices. 4. The most frequently collected, submitted and examined forms of evidence were fingerprints, firearms and biological (blood and semen). For the sites included in this study and for the time period reviewed, DNA testing was rarely performed across all offenses and was concentrated in homicides and, to a lesser extent, rapes. 5. Although rates of arrest and conviction in study sites were low, the study rates were quite similar to national arrest and conviction data (see Table 4). 6. The contrasts between rates of arrest, prosecutor referral, charging and conviction for the crimes of aggravated assault, burglary, and robbery with and without physical evidence 122 This document is a research report submitted to the U.S. Department of Justice. This report has not been published by the Department. Opinions or points of view expressed are those of
the author(s) and do not necessarily reflect the official position or policies of the U.S. Department of Justice. collected were all substantial and statistically significant. For the crime of rape, differences were significant for all decision levels except for prosecutor referral. 7. At the logistic regression level, crime scene evidence was a consistent predictor of arrest across all crimes, but a very low percentage of arrests actually had physical evidence examined before the arrest. The exact role played by forensic evidence at investigation and prosecution levels is complex and dependent upon many factors. 8. Post-arrest, the predictive power of forensic evidence varied by crime type and criminal justice outcome. Lab examined evidence was a significant predictor of case charges for aggravated assault and rape. Forensic evidence also was associated with sentence length for assault and homicide. None of the measures of forensic evidence, however, were significant predictors of case conviction regardless of crime. In all, few independent variables successfully predicted trial/plea outcome largely due to the very high rate in which charged cases resulted in conviction. 9. While collected forensic evidence was a consistent predictor of arrest across all offense types, the other consistent predictors of criminal justice outcomes were typically non-forensic, legal and situational variables: victim and witness reports, victim/suspect relationships, victim medical treatment, and arrest methods. 10. Very few reported crime incidents had forensic evidence that linked a suspect to the crime scene and/or victim (~2% of all cases, 6% of cases with crime scene evidence, and 12% of cases with examined evidence.) In terms of examined evidence, however, those percentages elevate to x% and y%. However, the conviction rate for the cases with linking forensic evidence was significantly higher than cases without such evidence. Furthermore, conviction rates were higher for offenses with two or more forms of individualizing evidence that associated offenders with crime scenes. The study results were consistent with previous research. Peterson et al. (1987) compared felony case filings from six jurisdictions through a random sampling from three calendar years (1975, 1978 and 1981) in order to assess the rates at which forensic evidence was used and its impact on case outcomes. Similar to the current results, their data indicated that forensic evidence had a significant effect on the clearance rates of assaults, burglaries and robberies. On the other hand, prosecutors preferred the testimony of police investigators and eyewitnesses when making decisions to charge, in part, because laboratory results were unavailable at the time of charging. This was particularly true in
property crimes (23%) in which forensic evidence was not submitted to the crime laboratories for analysis. The study makes the vital point that there are two kinds of backlog in forensic science. First, evidence submitted to crime laboratories might not be processed promptly, which creates a risk of ‘justice delayed’. Second, law-enforcement agencies do not always submit forensic evidence from unsolved cases for testing, which creates a risk of ‘justice denied’. The results of the present study not only support Strom & Hickman’s findings but, in fact, paint a more worrisome picture of the underutilization of forensic evidence. Forensic evidence not only goes unexamined in unsolved cases, but in the vast majority of all assault, burglary, rape, and robbery incidents. Only a small fraction of available forensic evidence present at scenes of serious crime is submitted to forensic crime laboratories and undergoes examination. A number of reasons have been established as to why evidence might not be submitted to crime labs. Law enforcement might not submit evidence if an investigator questions if a crime has, in fact, occurred and/or if the investigator questions if the case merits full investigation. Investigators may also not submit evidence if a suspect had not been identified, if the investigator believes the case will not be charged by a prosecutor, and because of delays in receiving laboratory results because of long turn around tines. Equally important, even if evidence is submitted, in many cases, the evidence is not analyzed. Data from the present study illustrate, that to a large extent, the decisions to analyze submitted evidence are directly and indirectly affected by a prosecutors’ assessments of the case. Implicit prosecutor approval is often needed for investigators to request a laboratory analysis and to avoid what otherwise would be viewed as an unnecessary use of laboratory resources. Investigators and prosecutors perceive laboratory resources as precious commodities that are not to be requested or consumed casually. 124 This document is a research report submitted to the U.S. Department of Justice. This report has not been published by the Department. Opinions or points of view expressed are those of the author(s) and do not necessarily reflect the official position or policies of the U.S. Department of Justice. Studies of the charging process demonstrate that prosecutors exercise their discretion and reject a significant percentage of cases at screening (Frazier and Haney 1996; Spears and Spohn 1997). This research also indicates that case rejections are motivated primarily by prosecutors’ attempts to “avoid uncertainty” (Albonetti
- by filing charges in cases where the odds of conviction are good and
rejecting charges in cases where conviction is unlikely. These studies suggest that prosecutors’ assessments of convictability are based primarily, although not exclusively, upon legal factors such as the seriousness of the offense (Albonetti 1987; Jacoby, et al. 1982; Rauma 1984; Schmidt and Steury 1989), the strength of evidence (including forensic) in the case (Albonetti 1987; Jacoby, et al. 1982; Nagel and Hagan 1983), and the culpability of the defendant (Albonetti 1987; Schmidt and Steury 1989; Swiggert and Farrell 1976). Several studies conclude that prosecutors’ assessments of convictability, and thus their charging decisions, also reflect the influence of suspect and victim characteristics. In deciding whether to go forward with a case, in other words, prosecutors attempt to predict how the background, behavior, and motivation of the suspect and victim will be interpreted and evaluated by other decision makers, and especially by potential jurors. As Frohmann (1997:535) notes, “concern with convictability creates a ‘downstream orientation’ in prosecutorial decision making, that is, an anticipation and consideration of how others (i.e., jury and defense) will interpret and respond to a case.” While forensic laboratories included in the current study did not analyze biological evidence and stains on a consistent basis, Appendix A shows that their use of DNA testing in such cases has grown substantially since 2003. While DNA testing procedures has the potential to individualize evidence and to link offenders to crime scenes and victims (Beaver, 2010), the present study has shown that even cases with strong forensic evidence are subject to investigator and prosecutor screening that assess the credibility of the victim and are amenable to defenses, including consent, that render DNA evidence less dispositive. It may be that stranger property offenses and those where ‘touch DNA’ is present, may constitute the offense category where DNA will have its major impact in the future. The views expressed in the Forensic Evidence Processing section of the May 2010 issue of Criminology and Public Policy (Vol. 9, Issue 2) raise some excellent questions that should be reviewed critically by the forensic field. Brief articles addressing unanalyzed evidence (Strom and Hickman, 2010), the independence of crime laboratories (Cowan and Koppl, 2010), and the benefits, imitations and ethical concerns of the searching of DNA databases (Beaver, 2010; Roth, 2010). Increased resources devoted to DNA analysis and database searching can certainly yield important results, but the costs and benefits to the criminal justice process must be assessed carefully. Research may show that the discriminating and individualizing power of DNA evidence has its greatest
National Institute of Justice. Impact of Forensic Science Research and Development. April 2015. Retrieved from https://www.ojp.gov/pdffiles1/nij/248572.pdf In crime labs across the United States, scientists and technicians are being armed with increasingly sophisticated technologies that they can use to help bring criminals to justice and prevent the innocent from going to prison. Innovations from forensic science research and development (R&D) are bringing new techniques to crime solving and increasing the reliability and efficiency of forensic testing. Just as medical research is crucial for advancing public health, sustained progress in the research underlying forensic science is critical for advancing public safety and the administration of justice. Strengthening science to improve justice is a key goal of the National Institute of Justice (NIJ). Toward that goal, NIJ funds both basic and applied forensic research. In addition, NIJ maintains partnerships with the National Science Foundation (NSF) and the National Institute of Standards and Technology (NIST) to promote innovation in forensic science. In 2014, NIJ and NSF jointly initiated an Industry/ University Cooperative Research Center to advance university and industry collaboration in forensic science R&D and in education. One of several NIJ-NIST working groups has developed best practices for the handling and preservation of DNA and other biological evidence. Other working groups in the partnership are addressing the interoperability of regional and national automated fingerprint identification systems (AFIS); developing procedures to limit investigator bias in examining fingerprints; and creating examination standards for a variety of evidence types in criminal cases. Since 2009, the Institute has invested more than $127 million in an R&D portfolio that makes it a global leader in the advancement of forensic science. 4 The Impact of Forensic Science Research and Development National Institute of Justice | NIJ.gov Strengthening Crime Laboratories Forensic science R&D in the 1980s laid the groundwork for advances in the 1990s and early 2000s that had a profound impact on crime laboratories. Although the scientific advances, particularly the growth of DNA
testing, provided more effective tools for analyzing evidence and identifying perpetrators, they also led to a dramatic increase in the demand for lab services. By the late 1990s and through the 2000s, demand outstripped the ability of the labs to respond quickly and efficiently. Today, scientists and technicians at forensic labs are under relentless pressure to produce results faster and at lower cost. NIJ employs a two-pronged approach to supporting forensic labs: • In the short term, NIJ awards grants to labs that cover the increasing costs of processing cases, assist in DNA backlog reduction and support ongoing efforts to adopt more advanced instrumentation and analytical methods. • In the long term, NIJ awards grants to scientists to conduct research, both basic and applied, that can lead to methods, techniques and technology that will advance forensic science and, ultimately, public safety and justice. Innovation is an essential way to assist crime labs. For example, high-tech robotic workstations can now process large numbers of DNA samples simultaneously, allowing crime labs to work more efficiently. NIJ-supported research helped in the development of fully automated systems that amplify DNA from small samples to determine a person’s genetic profile. The workstations not only make labs more efficient but also lower the cost of DNA processing. NIJ is also funding several projects that seek to apply more sophisticated methods to detect and analyze evidence. Examining evidence for trace amounts of blood or other biological material is time consuming for law enforcement and crime lab personnel, and it requires techniques that can compromise or destroy evidence. One NIJ-funded project involves developing a camera with multispectral and fluorescence imaging capabilities to detect and identify fingerprints, body fluids, stains and other residues at crime scenes. Such imaging technology would make it easier for investigators to find and process evidence while minimizing evidence contamination. Researchers working on another NIJ-supported project are developing methods that will allow investigators to identify the body fluids in a stain without destroying any of the stained material. Researchers are also exploring how to use one sample to determine multiple pieces of information, such as body fluid type and genetic information associated with identity. The Impact of Forensic Science Research and Development 5 National Institute of Justice | NIJ.gov Advancing Forensic Technology in the Field Law enforcement investigators, as well as scientists and technicians in crime labs, must rely on new technologies and scientific innovations to more efficiently identify, gather and process evidence related to
support for research will be essential to ensuring that crime labs keep pace with increasing demand. Assisting Law Enforcement Scientific advances already play an important role in solving crimes. Labs can analyze smaller pieces of evidence than ever before, and law enforcement officials can gain valuable information from evidence that, in the past, would have been degraded and unusable due to weathering or time. New technology also allows investigators to find and analyze evidence that they would likely not have found via earlier methods. One example of this increasingly sophisticated technology is a method that could help forensic scientists analyze dust and other particles that piggyback on carpet fibers to determine whether fibers found in different locations are consistent with having originated from the same source. In some instances, such a comparison could provide investigative leads associating a suspect or victim with a crime scene. Investigators can now use DNA and other evidence collected and stored decades ago to help identify and convict criminals who have eluded authorities for years and to exonerate prisoners who were wrongly convicted before today’s more sophisticated methods became available. A striking example of new technology solving a cold case occurred in 2009, when Milwaukee police tested evidence in a reopened case and eventually linked nine murder cases dating back to 1986. They identified Walter Ellis as the suspect in what were known as the North Side Strangler cases. Faced with the new evidence, Ellis pleaded “no contest” to charges that he strangled seven women. In 2011, he was sentenced to seven life terms with no chance of parole. One of the more difficult challenges facing police officers working in the field today is accurately identifying substances that may be illegal drugs. This problem has grown in recent years with the widespread use of ever-evolving novel psychoactive substances, such as “bath salts” and synthetic cannabinoids, which are specifically created not only to mimic the effects of other drugs but also to avoid being classified as illegal. These drugs can be extremely difficult to identify, and NIJ has responded to the problem by funding several projects focused on developing more accurate methods of identifying the parent drugs (the drugs as ingested into the body) and their metabolites (the forms of drugs after being processed by the body). The goal of the research is to make drug identification faster, easier, safer and more accurate. One study aimed at improving identification of drugs and their metabolites involves obtaining blood, urine and oral fluid samples from volunteers at electronic dance music festivals who have ingested drugs. The Impact of Forensic Science Research and
Development 7 National Institute of Justice | NIJ.gov Confirming the Accuracy of Bloodstain Pattern Examiners Crime scenes can present a variety of bloodstain patterns on assorted surfaces. To verify examiners’ accuracy in determining what happened at a crime scene based on a particular pattern, scientists asked analysts to review more than 700 patterns falling within six different pattern types. Generally, the results indicated that bloodstain pattern analysts had lower error rates when classifying patterns on rigid surfaces than when classifying patterns on fabric surfaces (13 percent vs. 23 percent). These rates varied by pattern type, and some patterns were more reliably classified than others. Researchers also found evidence of confirmation bias, meaning that when analysts were given a scenario that pointed deliberately toward the correct classification, they were more likely to select that classification for the bloodstain pattern. These results indicate that more work is needed to understand how the interaction of blood with different surfaces influences the observed patterns. NIJ has ongoing investments in fluid dynamics research with the goal of providing examiners with objective computational tools to assist in their analyses. In addition, the results of the bias study indicate that crime labs and law enforcement agencies should take steps to minimize extraneous information that analysts receive before they conduct an analysis. Examining Human Factors in Fingerprint Analysis The accuracy of latent print examinations and the extent of human error in fingerprint analysis have also been the subject of recent studies in the justice system. NIJ is funding experts who are examining the effect of human error in fingerprint analysis, especially the tendency to focus on data that confirm preconceived expectations. One of the early recommendations from the experts is that crime labs develop a “culture of openness” in which errors are identified, acknowledged and used to improve analysis and reduce the error rate. Standardizing Broken Glass Analysis Broken glass at a crime scene can often be important evidence for investigators. In hit- and-run crimes, for example, examiners can analyze glass fragments to see whether the characteristics of the fragments are consistent with samples taken from a suspect’s car. A team of scientists has developed two new standards for forensic glass analysis to ensure that testing is administered consistently in different labs. 8 The Impact of Forensic Science Research and Development National Institute of Justice | NIJ.gov Helping the Public Ultimately, forensic science R&D is conducted to improve public safety and ensure that justice is fairly applied. For NIJ, that means improving the information available to all
