Introduction
Crime can be defined as the breach of the laws and rules which govern a people. Such a breach would warrant the authority to give a conviction or a caution. However, crime is defined differently by different societies. Every crime violates the law; however, not every violation of the law is a crime, for example, a breach of contract. This would be regarded as an offence and not a crime. Crime is mainly regarded as an offences against the government, state, or the public. These crimes are executed by human beings mainly to other human beings on their bodies. During execution, contents of the body are normally left at the scene of a crime or on the clothing and weapons used during execution.
These body contents, mainly fluids have a fluorescent nature which enables their presence to be noted. This is done with the help of an ultraviolet lamp (UV lamp), which enables these body fluids to reveal themselves in a unique way when illuminated. The UV light also enables one to detect things that are at a distance, however, it does not show what exactly is observed but only the location. Criminals have been known to use dark textiles, on which the use of the Alternative Light Source (ALS) cannot detect the traces of body fluids (Schiro, 2012, p. 1). However, the use of UV has complemented these ALSs, where high-intensity UV light can detect such traces.
The body fluids which have fluorescent nature are semen, vaginal fluids, urine containing blood or other body fluids, sweat and saliva. All these fluids contain deoxyribonucleic acid (DNA), which is unique for every individual. In crime investigation, these fluids act as a very important source of information, the body can be said to be datum for crime detection. Also, in this category of data for crime detection are the fingers. This is because the fingers have prints that are unique to every individual. In this discussion, we will look at each of the fluids and areas on which they can come in handy for crime detection.
Use of body for crime detection
Semen
This is the fluid from the male reproductive organ which normally accompanies sperms during sexual intercourse. This fluid normally is released prior to ejaculation to neutralize the acidic nature of urine passed through the same route. This normally accompanies an erection and would be left in traces on any garment or surface with which an erect penis comes into contact. This can be a very good source of evidence in a rape case or attempted rape. Since in a rape or defilement case, the criminal always has an erection before committing the crime and any erection would be accompanied with the release of semen, the traces can be collected and a DNA test conducted to establish their origins in terms of the person (Akhtyrskaja, 2002, p. 1).
For example, during an attempted rape, the victim’s garments will certainly have trace marks of the criminal’s semen. Using the UV lamp, their location can be detected and then extracted. This is then followed by a DNA test to isolate the culprit from a pool of suspects. The DNA test is conducted on both the extracted sample and blood sample collected from suspects. In a rape case, however, the victim’s vaginal content is sampled and tested alongside other extracts from either the garments of the victim or the bed sheets if the rape occurred in the bed. At this point, it is important to note that, the victims should be advised not to change clothes or even take a shower after such an incident. Taking a shower or changing clothes would interfere with the evidence. It is also advisable not to clean or rearrange the scene of the crime for this same reason. Semen, therefore, is a very important component of the body as a datum in crime detection.
Vaginal fluids
These are the secretions from the female reproductive organ. They are produced when a female is sexually aroused and they contain the genetic information, DNA. These secretions can be collected either from spillage or directly from the female organ and be subjected to a DNA test to trace their origins. In crime detection, they would be useful in crimes of passion and rape. In rare cases where the offender is the male, vaginal fluids are expected to contain semen from the male. The vaginal secretion would therefore be helpful in the extraction of the sperm cells to be subjected to DNA screening to identify the male offender.
However, where the offender is a female, there are two case scenarios. The first scenario is where the vaginal fluids are released on either the victim’s garments or traces are found on the victim’s private organs. In this case, the traces are collected from the garments or from the victim’s male organ by wiping it with sterile tissue before being subjected to screening for DNA (Ramsland, 2012, p. 1). In the second scenario, the suspected female offender is subjected to screening. Her vaginal fluids are collected and tested for the DNA present. This can have two possible outcomes that are; the vaginal fluids would contain foreign DNA possibly from the victim, contained in semen which would be released into the vagina during the rape. On the other hand, the vaginal fluids would contain similar genetic material as the traces either found on the male victim’s private parts or his garments or on the traces found at the scene of the crime. It is therefore important that the victims of such crimes do not interfere with these possible sources of evidence either by taking a bath or changing their clothes.
Urine containing blood or other body fluids
In cases where an offender or a victim passes urine containing blood and other body fluids, this can be used in crime detection. Blood for example can be used to detect crimes of torture or to trace an offender who may be using a flush toilet. Other body fluids which contain DNA can also be used in tracing offenders in the same way.
An example is of a torture victim, where a suspected case of brutality and torture and injury to the lower abdomen would result in the injury of the bladder and the urethra. When these body parts are injured, bleeding occurs leading to the passage of urine with bloodstains. Therefore, urine with blood is a source of evidence that torture occurred.
On the other hand, in a murder case, for example, an offender may pass urine at the scene of the crime and if the urine contains blood or other body fluids, it can be used as a piece of evidence against the offender. However, this comes with the challenge of multiple users saying a urinal, where cases of the wrong identity might arise. Other body fluids like lymph can also be present in urine since, during water elimination from the body, lymphatic fluids may escape from the lymph nodes (Thompson & Cole, 2006, p. 42). This may also have a trace of the genetic material, DNA which is the benchmark for the identification of individuals without much overlap.
Sweat
Sweat is the excess water in the body released through the pores on the surface of the human skin. Sweat is also produced during physically involving activities that require a lot of energy and produce a lot of heat. Sweating helps release the excess heat thus regulating the body temperature. The sweat contains DNA and is easily detectable with intense illumination. During the course of committing a crime, the criminals normally use physical energy and, in most cases, wear heavy clothing including gloves in order to conceal their identity. This is counterproductive as it leads the criminals to sweat and leaves traces of their DNA on their protective clothing. Sweat is normally found on gloves, the inner surface of their masks, and door locks, in cases where the criminals spend a lot of time trying to break the locks (Bunch, 2000, p. 958).
The sweat traces under high intensity of illumination are easily visible and can be extracted then tested to identify the DNA content. With the knowledge of the DNA sequence, it is possible to track down the criminal offender and even to identify the criminal positively from a pool of them. However, it is a tricky situation where for example, a mask or the gloves used have been used previously by another person. This would result in a mixture of sweat from different sources with the final effect of incorrect identification of the offender. In such a case though, all the suspects’ positive for the DNA sequence isolated would undergo a further screening using a different means of screening.
Saliva
This is the liquid content of the mouth cavity. It contains body content which has DNA, a very important piece of evidence in crime detection. It can be left in traces on eating utensils, toothbrush, or other objects which comes into contact with the mouth. It is also left in traces during kissing, whether forced or voluntary. Saliva is mostly found in areas where you would find sweat. In crime detection, saliva comes in handy where for example, where the criminals have eaten food at the crime scene. The spoons used would be a very important source of evidence of who the criminals were. There have been several cases of a criminal breaking into kitchens and eating the food available before packing up the valuables from the scene of the crime.
In the scene where the criminals spend a lot of time talking, there are expected to be many droplets of saliva. These will appear on the inner side of the mask and surfaces of say tables and chairs. These droplets can also be found on doorknobs especially in cases where the criminals struggle to break the door while talking either to each other or to the to-be victims inside the house. Saliva can also be found in traces on the mouthparts of masks. This can be extracted from the masks which may be left at the scene of a crime or other areas from where such clothing may be left after the crime (Frank, 2011, p. 1).
Saliva also contains DNA and is detected under high intensity of UV light. It is therefore a very important and valuable source of evidence for crime investigators.
Fingerprints
Everybody, the world over has a unique fingerprint. Nobody has the same fingerprints as the other even identical twins. This has a very great significance to crime investigators as it helps in the identification of criminals. However, this requires that the criminal touches the object or victim with bare hands. They are two scenarios in this investigation. First, the criminal holds an object to execute the crime, or in the second scenario, the criminal holds or touches the victim with a bare hand before, during, or after the crime. In the first scenario, the criminal holds, for example, a gun to execute a crime like murder. If the gun is found at the scene of the crime, the fingerprints are taken and cross-matched with those of the suspects. In the second scenario, the criminal touches the victim of the crime with bear hands thereby leaving his or her fingerprints on the skin surface of the victim.
The use of fingerprints in crime detection can be done in two ways. One of the ways is by collecting the suspects and comparing their fingerprints to those collected from the scene of the crime. The other way is by comparing the fingerprints collected to those in the civil registration authority database. During registration of adult citizens in a country and even when registering for a passport, the fingerprints of these people are collected. This helps in the management of crime within the country. It is therefore important that people visiting a crime scene do not touch anything at the scene with their bare hands. This also applies to the investigators collecting evidence at the scene of crime since the appearance of their fingerprints on such pieces of evidence would interfere with the results of the investigation (Wertheim & Maceo, 2002, p. 62). Examination of fingerprints is a very important part of crime investigation and a significant demonstration of how the body can be used as a datum in crime identification.
Conclusion
In light of the foregoing discussion, it is apparent that the body in itself carries very pertinent components that can come in handy in crime detection. It has been shown that body parts, wastes and secretions contain DNA which is unique for every person. DNA is a genetic material that contains the coding information which determines a person’s characteristics. This technology is quite expensive and requires exceptional skills. This is one major demerit of using this technology despite its reliability. On top of the cost, the other demerit is the occurrence, although at very low rates; of people sharing quite a number of genes in their DNA. This results in the two or more people sharing the DNA codes having the same results during screening (Warren, 2009, p. 65). This would further inflate the cost of investigation since further tests would be required to pinpoint the real culprit. Apart from the unique DNA, a person’s fingerprints are also unique and no two people have similar prints. This is an outright way of isolating criminals; however, the criminals have come up with ways to beat the technology and no longer use their bare hands while committing crimes. This ensures no prints remain behind after the crime.
Reference List
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Bunch, S 2000 ‘Consecutive matching criteria: A general critique’, Journal of forensic sciences, vol. 45 no. 1, pp. 955 – 962.
Frank, M 2011 ‘Evaluating truthfulness and detecting deception’, Federal Bureau of Investigation, Web.
Ramsland, K 2012 ‘Forensic toxicology’, Crime library: Criminal minds and methods, Web.
Schiro, G 2012 ‘Collection and preservation of blood samples from crime scenes’, Louisiana State Police Crime Laboratory, Web.
Thompson, W & Cole, S 2006 ‘Psychological aspects of forensic identification evidence’, University of California, Irvine, vol. 2 no. 20, pp. 31 – 61.
Warren, G 2009 ‘Detecting deception from emotional and unemotional cues’, Journal of nonverbal behaviour, vol. 33 no. 6, pp. 59 – 69.
Wertheim, K & Maceo, A 2002 ‘The critical stage of friction ridge pattern formation’, Journal of forensic identification, vol. 52 no. 4. pp. 35 – 85.