The Role of Forensic Science in Criminal Investigation

Introduction

Forensic Science is also known as criminalistics. It is the application of science to civil and criminal laws, majorly on the side of crime during criminal investigation, as regularized by the legal standards of criminal procedure and admissible evidence (Turvey, 2013). Forensic scientists gather, analyse, and preserve scientific evidence by themselves during the course of an investigation. Notably, some forensic scientists travel directly to the crime scene to gather evidence. Others will opt to analyse the evidence brought to them in the laboratory by other people (Alison, 2013). In the late 15th century, medical practitioners in the university setting and the army, started to collect information regarding the cause of death. A French surgeon the named Ambrois,began to study the impact ,of violent death specifically on internal organs. Paolo Zacchia and Fortunato Fidelis, two Italian surgeons, laid down the modern pathology foundation. They studied the transformation that happens in the body structure due to the impact of a given disease (Machado et al., 2011). In the 18th century, people began to write about such topics. As the enlightenment era and rational values began to gather momentum in the18th century, investigation of crime became a rational procedure and more evidenced based. The massive use of torture to collect evidence was abandoned and the use of witchcraft and other external powers such as occult, ceased to influence the decision of the court (Mapes et al., 2015). The use of two examples of English forensic science in person’s legal proceedings showed the rising use of procedure and logic while investigating a crime at that time. In Lancaster, John Toms was arrested and tried for allegedly murdering Culshaw using a pistol. When Culshaw’s corpse was retrieved, a pistol wad that was found on his head wound, perfectly matched with a torn newspaper retrieved from Tom's pocket thus resulting in his conviction (Ribaux & Wright, 2014). For biology dissertation help, consider reaching out to expert and trained professionals in the field who can provide you with valuable guidance and support.

In 1816, the murder of a maidservant led to the trial and conviction of a farm labourer in Warwick. It was reported that she was drawn in a shallow pool. While carrying out the investigation, the police found an impression of corduroy clothing and footprints. Notably, there were grains scattered everywhere. The farm labourer breeches who were threshing wheat within, were examined and they exactly matched to the impression near the pool (Williams & Weetman, 2013).

Forensic science recognized disciplines

Forensic anthropology: define as the study of the human form through osteology and skeleton system is used to assess and evaluate the remains of human in a legal context. Some of the main functions of the forensic anthropologist include making individual or gender identification and body reconstruction from human remains Margot, 2011).

Forensic botany: involves the incorporation of plant science to criminal justice. The plant development application and identification of species can be used in the determination of a crime scene at a given location, calculation of the PMI portion and removal of the body before or after the death (Lawless, 2011). Forensic toxicology: In this forensic discipline, the primary focus is on analysis of samples linked to drug usage, poisoning, or death. Analysis of the forensic by the toxicologist consists of grouping to identify the substance, quantitative analysis to determine the measurement of the substance. The letter can be essential especially when determining the crime that has already been committed. For instance, when alcohol has been consumed.

Forensic pathology: It is also referred to as forensic medicine, this is a discipline that majorly focuses on the cause of death, and determination is done through corpse examination. A forensic scientist determines the exact cause of death and also tries to ponder all circumstances surrounding the death. An autopsy is often carried out by the pathologist upon request by the coroner or medical examiner (Robertson et al., 2016).

Cyber forensics: involves an analysis of evidence gotten from digital storage media and computers. The main purpose is to retrieve, analyse, preserve and rovide opinion acts about the digital information. Cyber forensic is widely used in cybercrimes however it can also be applied in civil proceedings. Cybercrime is perpetrated in all parts of the world. The level of coordination involves the usage of computer servers hosting operations in other countries in which the affected countries have no jurisdiction. This necessitates a timely and effective level of intergovernmental collaboration between victim states. Such corporations involve UK police, partners in international policing such as the Europol and regional organized cybercrime centres. Digital forensics has its origin from the computer evolution, which occurred between the late 1970s into the early 1980s. During the 1990s, the principle evolved in no organized manner and it was not until the next century that national policing will be instituted (Roux et al., 2012).

For any given field of study to be regarded as a science, it has to conclusively show study, description and investigation into the said field. Knowledge obtained must be repeatable. Finally, a review by peers must follow thereafter. One main problem encountered in digital forensics is the fact that the evidenced composed by a digital forensics’ investigator may not be reviewed hence may be expunged on the basis of not being verified. The full flair of science is therefore not always there for digital forensics in such cases. The lag in the development of this field could be attributed in part to the fast rate of development of digital technology leaving little time for forensics to catch up (Ludwig & Fraser, 2014).

Forensic Odontology: According to Julian et al (2011), Forensic odontology assists in identifying the victims in cases where the body is left in unrecognizable condition. It is often achieved by recognizing the victim's teeth, the alignment of the teeth and the mouth overall structure. Forensic dentists assist in a person comparative identification by studying and examining the anatomy and development of the teeth. It is usually used in criminal investigations involving analysis of the bite marks.

The scope of forensic science

The crime scene: This is an area or place where evidence can be collected to assist in providing an explanation of events. Margot (2011) denotes that inductive and deductive reasoning should be applied while processing a crime scene in order to understand and acquire knowledge concerning the events that happened at the crime scene. The purposes of the crime scene investigation are to assist in gathering, packaging, preserving, transportation and documentation of every single physical evidence found or traced at the crime scene. The relationship between the suspects and the crime scene can also be established by simply aligning the information gotten from to the scene of crime, victims, and witness interviews. The crime scene should be safely secured to prevent any possibility of contaminating the evidence. Appropriate labelling and packaging are used by the police while processing the crime scene to diminish hazards to the scientists.

Biological evidence include hair, teeth, and body fluids among others. Biological evidence is very important at the crime scene as it helps in the identification of the exact offender. Notably, it facilitate successful retrieval of what transpired at the crime scene. It is advisable to collect the biological evidence at the crime scene immediately after securing the crime area to avoid contamination. They gathered samples are examined and analysed by given techniques for detection through analysis of forensic DNA (Birzer & Roberson, 2018).

Chemical evidence: All chemical substances found at the crime scene. They include drugs, biological toxins, chemical weapons, and radioactive substances.

Trace evidence: Evidence such as soil, wood, fibres, gunshot residue, and footprints These evidences may give clues and hits that may be used to identify the victim. The trace evidence often plays a significant role in identifying the prime connection between the victim and the suspect. For example, a soil sample gotten from a shoe at the crime scene can assist in providing an important hint on the crime location thereby assisting in tracing the real criminal (Quinones & Daniel, 2012).

Physical evidence: They are part of the material object that is used as a fact in a crime scene or while presenting a criminal case. Items such as bullet casing, knives, and dental crown and bone fragments can all serve as physical evidence. The prosecutor must hold these physical evidences, in order to prove any crime in a court of law. The provision of something true contrasts the training of a scientist with extensive knowledge about the scientific method. For this reason, forensic scientists are faced with ethical challenges that require them to always stay focused on data or facts and to desist from uttering statements that are rather expected to come from the attorney. Establishing elements of the case is one of the roles of the forensic scientist. For instance, in an event where the police officer has confiscated a brown powder from the alleged criminal or the suspect, the role of the toxicologist is to determine whether the powder is a narcotic just like heroin that has a link to the crime scene, or whether the powder is just a typical substance (Rossy & Ribaux, 2014). In many scenarios, the analysis of the forensic is carried out on a material or object that has been gathered from the crime scene. Ironically, some of the presented evidence is the outcome of the interaction that happens between persons, presumably the assailant and the victim. The Locard's exchange principle denotes that every form of contact between two or more persons will always leave a trace. This implies that any form of contact between individuals can alter the material that can potentially serve as trace evidence (Roux et al., 2012).

It is important that all evidence gathered at the crime scene is well maintained before sending any form of evidence to the forensic laboratory. In this regard, any evidence coming from the crime scene must all be accounted for whilst conducting the investigation process, from that time trace or physical evidence is retrieved at a scene of crime and the analysis carried out at the forensic laboratory until presentation of evidence is done in the courtroom by the witnesses, many who are forensic scientists.

Physical evidence analysis

Trace or physical evidence gathered from the crime scene are taken to the crime laboratory or delivered directly to the forensic experts. The scientists may begin characterizing the evidence through qualitative or quantitative assessment. The analysis may be required in the identification of the evidential sample to affirm if the crime has been committed. According to Margot (2011), quantitative analysis is carried out in order to determine the measure of substance that has been discovered to help in confirming whether there is an extension of legal limits. Both qualitative and quantitative analyses have a bearing in entomological evidence. In a number of cases, the experts use comparison testing to assess physical evidence: the known object is compared to the evidential objects invalidated collections of references or databases. They can sometimes be compared to control experiments outcomes.

Determining whether the presented physical object is the actual evidence is the immediate step of forensic science analysis. The ability to correctly determine the evidential truth in the object majorly depends on the experience of the investigator. Notably, entomological evidence should be handled with a lot of caution and care to ensure collection of as many materials as possible even the ones that may not be used (Bitzer et al., 2016). It is important to collect the entomological materials immediately the crime is discovered. Additional evidence cannot be collected a month later to be used as evidence. According to Alison (2013), the entomologist needs to see to the biggest maggots belonging to a range of species in order to approximate the post-mortem interval on the moderately fresh corpse. Making determination on collection of a small sample of maggots found from the first larval mass can greatly compromise the ability of the entomologist to accurately approximate the time of death.

After an item has been determined as physical evidence, processing of the object takes centre stage to identify it. Generally, this implies the grouping of the evidential object into different classes or categories. Bloodstains, hairs, and other body fluid must be recognized to determine if they are from humans and if not, they are categorized as an animal sample (Erol-Kantarci & Mouftah, 2013). For instance, adult flies pouring undigested food such as blood can create fly spots on a given surface, which may be indistinguishable from some type of blood spattered at the crime scene. An initial blood spots analysis is essential in order to group the spattered blood as bloodstain or some object such as insect artefact. Similarly, powders, paint chips and other material object must be identified to facilitate correct and accurate grouping. Comparisons are mainly done between the known database and the object of interest. The classification process can equally result to object exclusion from the grouping. Such cases are found in glass fragments or fibres, which may be generally grouped or classified but later noticed to be different from the ones found from the victim and even the crime scene. In that case, the object is excluded since it does have a bearing like the ones found in the crime scene (Bitzer et al., 2016).

Individualization

This is an advance level of identification or rather narrowed classification that entails comparison testing in order to differentiate an object as unique or being different from others in the same grouping. It can also be used to recognize that an object bears similar physical evidence when compared with an object from another class. The letter is often carried out when a tire tread marks or shoeprint impression from a crime scene are matched with the test impressions. Further identification of the impression can be done by comparing with particular brand characteristics and applying databases provided with information from the manufacturing company. The identity of the perpetrator such as rapist can be individualized or determined through DNA profiling on semen, blood or other body fluid (Osterburg & Ward, 2013). If the individual has a previous criminal record, the fingerprints or DNA sequence can be compared with that present in the database such as CODIS. Evidence from an insect can similarly be determined through the use of voucher specimens, DNA analysis and dichotomous identification keys to identify the species which was gathered from the crime scene. Just as classification, individualization can similarly lead to exclusion or negative identification. For instance, an alleged victim may be acquitted when the DNA or the fingerprints are found to be different from those obtained from the crime scene.

Reconstruction

Reconstruction is the Forensic scientist's investigative efforts that display the application of the scientific method. This is owing to the fact that the reconstruction process entails the use of physical evidence and the findings obtained from analysis of the evidential object to attempt piecing together the crime events. It can be regarded as analogous used to test for the hypothesis (Margot, 2011). Reconstruction of the crime scene needs formulation of the explanations to be used in accounting for the collected evidence, explanations testing and refining the previous hypothesis based on the results of the test. This is necessary, in order to perform additional testing. The reconstruction outcome can give a clue on the events that happened during, before or immediately after committing the crime. The information is important especially in refuting or corroborating the type of statements made by the suspect, eyewitness, or victim. This type of forensic analysis gathers the information that is mainly theory of speculation based largely on physical evidence.

Generally, intelligence information gathering associated with criminal activities have no bearing on natural sciences and is more in agreement with disciplines aimed at profiling. The transformation in the global interactions amongst various groups such as terrorism has however broadened the forensic science scope. The act of terrorism has lately become sophisticated. In countries like the United States, many forensic scientists put efforts in a bid to collect information about the terrorist group through an analysis of the components or weapons that have been used to build the devices so as determine the location or suppliers of the material. Insects have been used, bombs or other explosives can be tested by using necrophagous fly larvae with a hope that the culprits can be identified. This kind of approach depends on the assumption that a terrorist group or cell has an already set up modus operandi, thus implying that the terrorist is using explosives (Alison, 2013).

Application of forensic science

Forensic science is applied in the investigation of several issues that are linked with administrative, civil, and criminal matters. Majority of forensic scientists handle administrative and civil cases or rather issues that are related to security. The main functions performed by the forensic scientists are provision of expert testimony, collection of evidence at the scene of the crime and to analyse the physical evidence, presented to them. They spend most of their time applying methodologies and principles of their discipline to analyse the elements of the crime.

Conclusion

As evident above, Forensic science is a powerful and versatile tool in the criminal investigation. Forensic technique and tools must be aided by the experience, knowledge, police, intuitive detective and other roles of experts. Forensic science makes use of all gathered evidence from the crime scene to come up with a solution of a question originating from the crime scene. The outlined processes and procedures are cautiously and carefully followed (Julian et al., 2011). The searching pattern plays a major role in the collection of physical evidence and other forms of evidence. The DNA experts use kits and technical tools to recover fingerprints from the crime scene. The tyre tracks and shoeprints provide a clue towards the identity of the crime, gait and height of the criminal. Forensic science is very important in everyday life since it helps in the investigation of crimes thus justice is upheld.

References

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