This project will be discussing how DNA evidence has assisted the UK’s criminal justice system in identify defendants that are involved in crimes, and to what extent has it done so? To be able to answer this question, the historical side of DNA evidence will need to be highlighted and what developments have been made since its inception. Another thing that this project aims to do is, to determine whether the standard and burden of proof of DNA evidence is enough to identify defendants that are involved in criminal activity. The reason for exploring this topic is because I have had concerns about the efforts of the criminal justice system to try to convict criminals on the sole basis of forensic evidence in particular DNA evidence. I have observed that the establishment of guilt requires some scientific and technological methods and it is to this extent that the topic has become of interest to me with a view to truly discover whether they have proved useful in this regard. (more will be added to this at the end)
What is DNA evidence?
According to Archbold practitioner text on evidence, states that “a DNA profile is not unique; it expresses probabilities. It is a fallacy to confuse the match probability with what is known as the likelihood ratio. There are two distinct questions:
- (a)What is the probability that an individual would match the DNA profile from the crime sample given that he is innocent?
- (b)What is the probability that an individual is innocent, if he matches the DNA profile from the crime sample?”
DNA is deoxyribonucleic acid, a self-replicating material which is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
Evidence is every type of proof legally presented at trial (allowed by the judge) which is intended to convince the judge and/or jury of alleged facts material to the case.
Evidence comes in many different forms. It was first discovered during the 19th century and was a part of the developments in science and scientific knowledge as well as improved scientific equipment. This include microscopes, photography and medical discoveries related to blood.
The first type of accurate physical forensic evidence used was fingerprints. Which was first discovered by Galton in the 1800s. Fingerprints became a very popular and useful to those in the scientific field. Fingerprints became very important to investigations, it was also a big scientific discovery as everyone has a different print to one another which has help to now knowing who the individual is. This led police forces to start creating fingerprint files to aid criminal investigations. People were able to be identified at crime scenes by the traces left behind that were unique to them, but just fingerprints alone were not able to prove the guilt of a suspects. This was because evidence of presence was not evidence of complicity.
Prior to fingerprints, criminal investigators relied on the footprints of shoes to find the suspect of a crime. But this method became less popular to use, this was because it came with some problem that needed to be addressed in order to be for it to be successful when trying to prove the guilty of a criminal. This included finding ways to raise the accuracy and reliability of the method so that it would not lead to the wrongful convictions of innocent people. One way in which this was problem was solved was through the launch of the Footwear Intelligence Technology. This database allowed police to access footprints from previous crime scenes. Also, the police themselves can enter information on to the database to help with an ongoing investigation that they believe may be linked to one another. But this new method was not launched until much later on.
There are other forms of forensic evidence that can used in a criminal court case. These forms of evidence all require their own method and also have different databases, in which information is placed on. The more traditional types of forensics include Drugs, Toxicology, Firearms, Footwear Patterns, Fingerprints, Blood Splatters, Fibres, Fire Investigations and DNA. Information from these types of forensics can be used as evidence to help to find the person that committed the crime. This text will be focusing on DNA evidence and how it has assisted the UK Criminal Justice System in identifying defendants. An example of this is the database that finger prints are placed on, this is shown as In the UK approximately 50,000 offender each year, are identified as being at the scene of a crime through their fingerprints. That were left by them. There are also the less traditional methods that include Character Evidence, this is a testimony or document that is used to prove that someone acted in a particular way base on the person character. There is Circumstantial Evidence, which is also known as indirect evidence. This is the type of evidence that is used to infer something bases on a series of facts. There is also Digital Evidence, these are digital files from an electronic source. Evidence also includes direct evidence, which is the most powerful type of evidence as it has no interference. Testimonial evidence can also be used to prove the guilt of a criminal. The development of physical evidence has led to the development of other forms of physical forensic evidence that can help to aid investigations. This included things such as blood, hair and DNA analysis. Which has made a big difference in court and has also helped with conviction of suspected criminal. The focus of this essay will be DNA evidence. According to Archbold practitioner text on evidence, DNA evidence is
There is a separate database that DNA evidence information is placed on. The data from those databases shown that DNA evidence has had a positive effect as it is leading to the convictions of criminal. An example of this is on average 25,000 DNA matches made each year, between the crime scene and the offender. With the matches to those particular DNA samples the perpetrator of a crime can be identify and get the punishment that they deserve.
The National DNA database produces over 2,000 DNA matches a month and has a match rate of over 60% with DNA profiles obtained from sample taken from a crime scene or victim. This is a high number of matches and is great as it shows that the method and technique in which the sample is obtained and analysed is able to identify the person or people that my have been involved in a crime.
Standard of evidence in the UK Criminal Courts
The standard of proof in the English legal system, is beyond all reasonable doubt. This is the standard that must be met by the prosecution’s evidence in a criminal prosecution: that no other logical explanation can be taken from the facts except that the defendant committed the crime. this overcomes the presumption that a person is innocent until proven guilty. If a piece of evidence can be proven that beyond all reasonable doubt that it can be no one other than the defendant, then they can be found guilty of the crime.
In most criminal case the burden of proof is placed on both the prosecution and the defence, to prove that they have the stronger case against the opposition. However, in the law of evidence the “Evidential Burden is not really a burden at all, it is discharged by raising an issue as to the matter in question to be considered – discharged by evidence short of proof.”
If both the standard and the burden of proof are both proven, then there should be no question that the evidence that is given points in the direction of the suspected perpetrator. If so, there should be no reason why that person can not be found guilty.
On top of the fact that the standard and burden of proof are proven there are some steps that need to be taken to make sure that the evidence is able to assist the UK Criminal Justice System in identifying defendants. When collecting evidence from a crime scene the main aims are to collect the evidence in such a way that it can be used in court. The evidence will be preserved in such a way so that it can be analysed. The scientist will also want to reconstruct the crime scene and lastly identify the person who is responsible for the crime. When the forensic scientist first arrives on the scene, they will put on protective clothing such as gloves, masks, hair nets etc. This is to make sure that nothing from them contaminates the evidence. To collect the evidence, they will take pictures of the crime scene before they touch or move anything this is to make sure that they preserve the scene and to also be able to mimic it physically and digitally if it is necessary. After the pictures they will collect trace evidence. Trace evidence includes things such as gun- shot residue, chemical glass paint and others. To remove this the person investigator may use tweezers or a vacuum or a knife. But if the crime involved a gun the clothes of the victim would be taken is as evidence. DNA that comes in low-level forms will also be collected by using a swab to swab down area that may have been in contact during the crime.
To follow on from that the investigator of the crime will also need to collect items that could possibly contain biological evidence. This may include items of clothing, the victim, etc. The last step in collecting evidence is locating and collecting fingerprints that may have been left by the preparator. If all these steps are carried out correctly the evidence that has been acquired will be taken to the laboratory for analysis. The evidence that has been collect will be taken to the laboratory for analysis. This process could possibly be where some critical mistake are made. And with theses mistakes that are made innocent people end up in prison. However, some time the evidence is intentionally tampered with so that and innocents person will take the fall for an actual criminal. This is unjust and unfair. When the evidence is in the laboratory it must go through so processes to find out who is the true owner of the evidence. But each form of evidence will go through a different process.