The Role of Science in Criminal Investigation
When a person or a group of persons is suspected and arrested for an alleged crime, the suspicion and arrest do not mean conviction in any way. Having been arrested or not, proper investigation into the alleged offence or crime should be carried out, the police officer on duty at that moment should intensify effort to ensure that necessary investigations are conducted in respect of the arrest made. Beside this, there are some other methods employed in investigation of crimes.
In this discussion, we shall look into the role of science in criminal investigation. "^he term "science" is used to refer to the knowledge about the structure and behavior of the natural and physical world, based on facts that can be proved by experiments. Science is not art. Scientists prove their facts or arguments experimentally. "Forensic Science" refers to the branch of science that deals with detection of criminals. The police may use scientific stills in testing and solving crimes. It has been defined as the science used to detect and prosecute crime. In investigation into certain crimes, science plays significant roles. In several cases, forensic science has been used to determine whether a crime has^6mmitted and who committed the crime. It has always been used to link suspect to a scene of crime. It has always been used, too, to support or disprove Alibi or confession. Alibi refers to evidence showing that someone was not in a place when a crime was committed. Severally, Forensic "science" has been used to convict the guilt or acquit the innocent. The forensic science often helps to detect when a crime was committed.
Forensic science performs many functions; we 'have many branches of Forensic science. The branches are grouped based on the areas of crime they are employed, Each section or branch particularly deals with certain areas in the processing of items of evidential value. Below are the major sections in Forensic science with brief explanation on each of them, in regard to how they are used to achieve the intended purposes.
(a.) Finger prints section:- Finger prints under this units are identified, classified and processed in such a manner that they would be accepted in court of law in respect to an alleged crime. It is also the responsibility of this section to compare latent finger prints finger prints collected at the scene of crime. The section widely treats any case concerning finger prints in accordance with the law.
(b.) Ballistic/ tool mark section:- In this section, experts examine bullets, their fragments and firearms used in the commission of a crime so as to know their identity. This branch also determines the distances and angles of shots and identifies the sun shot power on subject as proof of recent use this section examines other tools used in commission of crime
(c.) Chemistry section:- under this section, chemical analysis of chemical substance is done to interpret information to identify the origin and distribution of an item of evidence. This unit is also capable of discovering any guilty person who escaped from the scene of an accident.
(d.) Document section: In this section, false or forged documents or materials are identified electronically. It is also the responsibility of this document section to conduct ink analysis to determine whether the ink found, on a suspect and the ink used in writing are the same. This section also traces the machine used in producing various documents. An example is the manipulation of results and production of counterfeits etc,
(e.) Biology section: This section of Forensic science is used to perform numerous functions in identifying problems: analysis of blood to determine whether the blood is human or animal blood; conduct of necessary tests in order to identify people when there is dispute as to maternity or paternity; biological section of Forensic science can also be used to conduct tests and proofs whether rape has been committed or not.
(f.) Photography Section: In this section, photographs will be taken in regard to an alleged crime. Photographic materials such as camera are supplied to effect accurate pictures and other photographic items of evidential value. The photograph of the scene of a crime or the victim of crime will be taken to corroborate the facts.
(g.) Polygraph Examination and voice identification section: - This section identifies reconciled voice of suspects. It also makes use of an instrument known as polygraph machine to detect when a suspect is telling lies. The device is very important because it helps to identify lies told by suspects.
From the foregoing, it is apparent that some crimes may be detected scientifically with the use of various scientific methods.
However, our attention should be drawn to one thing collection and handling of the specimen. The expert who is discharging the duty should ensure that the correct specimen are collected and processed so that one will not be unlawfully incriminated, or so that one will not become "a criminal” of a crime which one knows nothing about. More so, specimen should not be handled with bare hands during its collection and processing.
When somebody is accused of a crime which should be investigated scientifically, the suspect should not be intimidated to submission. In the place of intimidating him to submission, the alleged crime should be investigated by the means of forensic science. Pieces of advice also go to an accused person who may refuse to be tested or who may refuse to conform to the instructions of the agents carrying out the legal exercise. Suspects should always agree with the results of forensic science provided the exercise was legally and correctly carried out. Let us join hand and check the increasing crimes in the society.