The Science of Evidence

The Science of Evidence

Evaluate the evolution of forensic science, focusing on the types of scientific analysis conducted in crime laboratories.

The use of forensic science dates back to many centuries when fingerprinting was one of the main applications. In 1892, a system was established by Sir Francis Galton to classify fingerprints, after which Sir Edward Henry developed a system in 1896 called the criminal fingerprinting technique. James Marsh came up with a chemical test in 1836 that was used to detect arsenic that was used in a murder trial. In 1930, Karl Landsteiner classifying the human blood into different groups, after which he won the Noble Prize. His work created a path for the use of blood in different criminal investigations. During the mid-1900s, tests were developed that used semen, body fluids, and salvia to increase the precision of blood tests. Advanced forensic techniques emerged in the 20^th century and were applied in crime scenes evidence (Casey, 2011). In 1910, the first laboratory for police crime was set in France by Edmond Locard, a work that pioneered in forensic criminology. In 1924, August Vollmer set up the first American crime laboratory for police in 1924, after which the Federal Bureau of Investigation (FBI) was set up in 1932 (Houck & Siegel, 2009). By the end of the 29^th century, forensic science had gained an array of high-technological tools for analyzing evidence for DNA analysis from polymerase chain reaction (PCR). This advanced to various techniques of digital fingerprinting through the use of various computing capabilities.

Explain how the changes in science and evidence processing over the last century have affected the criminal justice system.

The evolution of science and evidence has affected the criminal justice system positively in that it has aided in the establishment of guilt and innocence of suspects. Unlike before, when the processing of criminal justice-involved uncertainty, the evolution of forensic science has enabled investigators to increase confidence in their investigations for death ad crime. Today criminal justice system now applied forensically to solve cases by exposing mistakes in investigations. It has helped law enforcement to solve crimes and gain convictions, an aspect that has improved the criminal justice system.

Describe at least four major types of scientific testing conducted by crime laboratories

• Trace evidence refers to materials such as fibers and hairs often transferred from an individual or object after the crime. This may include animal hair, carpet, wood fibers, feathers, and human hair, among others. DNA evidence includes samples from the crime, including saliva, blood chromosomal DNA, and body fluids. Other samples include teeth, body fluids, bones, air, blood, and saliva, among others, for crime investigation.
• Drug testing investigates illicit drugs such as powders or unknown pills used in the crime (Cook & Odom, 2013). Presumptive tests are also carried out to test the use of chemicals such as heroin, among other chemicals.
• The testing of explosives examines and identifies the explosives identified at the scene of the crime. Laboratories often examine whether an explosion occurred and the components that were used to develop the bomb. Switches, chemicals, detonators, are also characteristic in the chemical investigation.

Describe the evidentiary value of the four major testing processes identified

Testing is beneficial in that it helps forensic scientists to analyze and examine varying types of evidence from different crime scenes in a manner that enables them to establish objective findings (Casey, 2011). The findings could assist in the prosecution and investigation of crime perpetrators, an aspect that can help free an innocent individual from the consequences of arrest and suspicion.

Analyze the current standards (based on case law) for admitting scientific evidence at trial, specifically addressing the four types of scientific testing identified in your paper.

While scientific evidence is known to strengthen cases, it can be excluded from a trial if it fails to meet particular specifications. Before it can be considered factual evidence, investigators must establish a scientific theory in the scientific community that is accepted generally as being true. Trace evidence is admissible as reliable forensic evidence if it has been around for very long and has been proven reliable with regard to fingerprint matching. Explosives testing such as laser speed guns and radar are considered valid to test the speed of a car and is often admitted as reliable evidence (Kahan, 2013). Scientific evidence submitted at trial by the scientific community without any solid foundation may be rejected at trial as invalid. DNA evidence must undergo a series of mini-trials before it gets accepted as valid at trial. Regardless of the evidence presented, the judge at trial should instruct the jury that the presented evidence can be considered by them for the stated purpose.

References

Casey, E. (2011). Digital evidence and computer crime: Forensic science, computers, and the internet. Academic Press.

Cook, B. G., & Odom, S. L. (2013). Evidence-based practices and implementation of science in special education. Exceptional children, 79(2), 135-144. https://doi.org/10.1177/001440291307900201

Houck, M. M., & Siegel, J. A. (2009). Fundamentals of forensic science. Academic Press.

Kahan, D. (2013). Making climate-science communication evidence-based. Culture, politics, and climate change: How information shapes our common future, 203-220.