Criminal Forensic Analysis

Nowadays, DNA is a crucial component of a crime scene investigation, used to both to identify perpetrators from crime scenes and to determine a suspect’s guilt or innocence (Butler, 2005). The method of constructing a distinctive “fingerprint” from an individual’s DNA was first described by Alec Jeffreys in 1985. He discovered regions of repetitions of nucleotides inherent in DNA strands that differed from person to person (now known as variable number of tandem repeats, or VNTRs), and developed a technique to adjust the length variation into a definitive identity marker (Butler, 2005). Since then, DNA fingerprinting has been refined to be an indispensible source of evidence, expanded into multiple methods befitting different types of DNA

Human DNA is very similar to one another, but only about 0.1% is different from the next person. That 0.1% can tell a person’s eye color, hair color, and other physical features. DNA analyst are able to take a drop of blood, the size of a dime, and duplicate the number DNA found in that drop. With the ability to duplicate DNA, analysts can have a back-up, in the event a human error were to occur. Analyst can tell you exactly where your ancestors came from and the percentage that is still inside your DNA. DNA is a very powerful tool that can identify a murder if the individual left any blood, saliva, skin tissue, hair or semen. The education needed to be able make use of the DNA consists of a great deal of science classes.

The Australian Institute of Criminology has produced documentations explaining “the technique of ‘DNA identification’ compares the DNA of two bodily samples to ascertain whether or not they came from the same human being. Identity of DNA in the cells across both samples implies that the samples are derived from the same person (or identical twins); non-identity implies different human sources.”

DNA testing is a critical and accurate tool in linking accused and even convicted criminals for crimes, and should be widely used to assess guilt or innocence before jail sentences are imposed. It was started up by scientists Francis C. Crick and James D, Watson in 1953 as they had described the uses, structures and purpose of the DNA “deoxyribonucleic acid” genetic fingerprint that contains organism information about an individual (testing

Due to the uniqueness of DNA it has become a powerful tool in criminal investigations

DNA forensics can also narrow down suspect pools, exonerate innocent suspects, and link crimes together if the same DNA is found at both scenes. However, without existing suspects, a DNA profile cannot direct an investigation because current knowledge of genotype-phenotype relation is too vague for DNA phenotyping. For example, a profile from a first time offender that has no match in any database may give the information that the criminal is a left handed male of medium stature with red hair and freckles. It would be impossible to interview every man who fits that description. However, with available suspects, DNA forensics has many advantages over other forms of evidence. One is the longevity of DNA. Although it will deteriorate if exposed to sunlight, it can remain intact for centuries under proper conditions (Sachs, 2004). Because DNA is so durable, investigators can reopen old cases to reexamine evidence.

Deoxyribonucleic acid (DNA) has been used to analyze and prove innocence or guilt of suspects of crimes with great accuracy. DNA is part of everyday life. It is the heredity material in humans and almost all other organisms. While being part of an investigation. DNA has helped to solve crimes. There is a couple ways that DNA left behind can be tested to solve a crime. Either if the suspect has been caught and or had his or her DNA tested, or if he or she has left behind any biological evidence. Which then needs to be tested to see if it matches the DNA found in the crime scene to his or hers DNA. The result to this comparison may help establish if the suspect committed the crime.

Identification means the steps needed in the analysis of unknown fluids to see what the substance is (“Biology,” 2016). Individualization determines whether a certain individual may or may not be the donor of a bodily substance by examining various markers (“Biology,” 2016). Processing biological trace evidence uses highly complex, automated technology to create a DNA profile that helps the investigators through the association of suspects to victims and to crime scenes (“Biology Services,” 2017). By using techniques such as polymerase chain reaction (PCR), forensic biologists can use variable markers found on the regular chromosomes (STR’s), the sex chromosomes (Y-STR’s) and within the mitochondrial DNA to distinguish one person’s DNA from another to a high degree of certainty (“Biology,” 2016). Forensic biologists are involved in assisting investigative agencies because police were led to Bernardo by a police sketch (“Serial Killers: Paul Bernardo and Karla Homolka,” 2013). The police took DNA (hair, blood and saliva) from Bernardo as a matter of routine to test it against specimens found on a rape victim’s clothing (Butts, n.d.). Forensic biologists were able to name the substances left on Kristen French’s body and match it to Bernardo’s DNA by processing it. On February 17th, 1995, Bernardo was arrested for the murders of Mahaffy, French, and the Scarborough rapes (Butts,

There have been many incidents where cases have needed a solid prosecution in order to convict the defendant in a murder or rape case. This is where DNA Testing comes in to help. By taking a DNA test, a person can be found guilty or not guilty. If a person claims they have been raped there can be a sperm sample taken from the suspect in order to prove that he is guilty or not. In addition, in a murder case there can be blood taken from the suspect so they can tell of his innocence. There are several ways to determine whether a person is guilty or not by this method. Many cases have begun to use this method saying that it is foolproof. People say this is the method of the future of crime

DNA profiling is a standard tool used to help with criminal investigations. This is impactful in the field of forensics to determine and identify suspects of murder. For example, almost 50 years after the crime, DNA provided evidence in the murder of Mary Sullivan by taking a sample from the nephew of the suspect in her murder. As such, it was clear the Boston Strangler was Albert DeSalvo. (Philip Bulman, February, 2014) DNA profiling is also imperative in identifying murder victims such as Kerry Graham and Francine Trimble, who became missing in December, 1978. Due to advanced knowledge in forensic science, a DNA match identified the victims in December, 2015. (Linda Williams, 2016) DNA profiling is conducted first by obtaining a DNA sample from a crime scene, suspect, victim or other evidence. The next step is to amplify sequences to make the DNA sample larger. Finally, gel electrophoresis is used to compare regions of the amplified DNA to determine which samples are from the same individual and which are unique. There are several profiling techniques such as polymerase chain reaction which targets and quickly copies segments of DNA from even minute amounts of blood or tissue. Another profiling method is short tandem report analysis which repeats short sequences of DNA to determine exact matches between relatives and unrelated individuals. As referenced above, gel electrophoresis compares fragments of DNA by separating from different sources. Lastly, there is RELP analysis

With regard to the US, where social science and STS research have, focused less on forensic databases and more on the production of expertise and evidence in court, Jay Aronson provided a historical account of the early practices, the scientific and legal controversies, and the ultimately successful acceptance of forensic DNA evidence in court in 2007. Another particularity of social science and STS research in this domain is that it has so far mostly concentrated its “high end” forensic technologies, namely those which received a lot of public attention because they were new, because stakeholders in the criminal justice system struggled to determine the parameters of scientific reliability and admissibility, or because they were prominently featured in the media. While the use of DNA analysis for police investigations and forensic casework dates back to the late 1980s, the second half of the 1990s marked the beginning of the quest to render DNA profiles systematically and routinely searchable and minable by setting up centralized DNA databases in many countries around the world. A DNA molecule is a long, twisting chain known as a double helix. DNA looks pretty complex, but it's really made of only four nucleotides: Adenine, Cytosine, Guanine, and Thymine. These nucleotides exist as base pairs that link together like a ladder. Adenine and Thymine always bond together as a pair, and Cytosine and Guanine bond together as a pair.

Forensics are one of the most supportive way we make decisions today. It has helped judges and the jury of the court prove that the person is either guilty or innocent. It completely changed the way the prison system on how it convicts the felons. Not only does it help lawyers it can also be used against others. Until it was discovered those who had prior been convicted of a crime did not get a fair trial. Forensics are usually for those who are fascinated with solving crime or are intrigued with crime or murder shows or situations. (good job!!)

Today DNA is used for the process of solving crimes, and it all started in England. In the early 1980 's in the English countryside the police were trying their hardest to find the man who was raping and murdering young teenage girls. The police had used all their resources and the investigation had reached a devastating end until they relied on one scientist who had invented what is now used with almost every crime today.

Forensic science has assisted law enforcement agencies across the nation with solving crimes with well-known techniques to include but not limited to fingerprint analysis, DNA analysis, ballistic analysis, and any type of digital forensics. These types of forensic analysis have become very popular with jury’s during trial because of shows like CSI: Crime Scene Investigation, NCIS: Naval Criminal Investigative Services, and Bones. What many jurors do not understand is what happens on television does not represent what actual crime scene investigators and forensic examiners do every day. Television shows like these show that forensic sciences are flawless.

DNA fingerprinting is a scientific technology involving the extraction, replication and arrangement of strands of an organism’s DNA. This results in the formation of a genetically distinctive fingerprint that is unique to the organism which the DNA sample was originally extracted from. Because of the specificity of a DNA fingerprint, the application of this technology can have a substantial influence on many aspects of society. Accessibility to a DNA database allows for higher efficiency in forensic investigations, personal identification, maternal and paternal testing. The availability of a national database to police officers and forensic scientists would equate to increased productivity in investigations and prosecution of suspects in a