Marina DauerSkyline High SchoolRegion 8AThe Other Forensics: Exploring DNA EvidenceHook/IntroWe all know the feeling. You eagerly tell someone that you are on your school’s forensics team. You are thinking of early mornings, trophies, and talking to walls. But instead, they ask- “Forensics? Like, with dead bodies??”. This all too common misconception may be irritating, but it introduced me to the world of forensic science.
This field has grown significantly in recent years. In particular, DNA evidence has become much more commonplace in the courtroom in the last three decades. Currently, all 50 states use DNA testing, especially in violent crimes such as murders.
DNA is very reliable and can lead to successful convictions or exonerations. However, there are also many issues with the use of DNA evidence. PreviewTo fully understand the complexities of DNA evidence and its use in the judicial system, we must first- sample information about DNA’s history of use in court cases, next- uncode the pros and cons of using DNA evidence, and finally- make a ruling and determine how DNA evidence should be utilized in the future.Background- What is DNA evidenceIf it’s been a while since your sixth-grade biology class, don’t worry. We can start by identifying what DNA is and how it can be used to make convictions. DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. The human genome is made up of 3 billion nucleotides, which are 99.
9% identical from one person to the next. The 0.1% variation, therefore, can be used to distinguish one individual from another.
It is this difference that can be used by forensic scientists to match specimens to an individual with a very high level of certainty. The complete DNA of each individual is unique, with the exception of identical twins. A DNA fingerprint, therefore, is a DNA pattern that has a unique sequence such that it can be distinguished from the DNA patterns of other individuals. DNA fingerprinting is also called DNA typing. The biological materials used to determine a DNA profile include blood, saliva, urine, hair, teeth, bone, tissue and cells. Investigators collect items that could have been touched or worn by persons involved in a crime.HistoryDNA profiling was originally developed as a method of determining paternity, in which samples taken under clinical conditions were examined for genetic evidence that could link parent to child.
It first made its way into the courts in 1986, when police in England asked molecular biologist Alec Jeffreys, who had begun investigating the use of DNA for forensics, to use DNA to verify the confession of a 17 year-old boy in two rape-murders in the English Midlands. The tests proved the teenager was in fact not the perpetrator. The actual attacker was eventually caught also using DNA testing.
The first DNA-based conviction in the United States occurred shortly after in 1987 when the Circuit Court in Orange County, Florida, convicted Tommy Lee Andrews of rape. The first state high court to rule in favor of admitting DNA evidence followed just two years later in West Virginia.According to Forensic Magazine, in the early years after these groundbreaking cases, the admissibility of DNA evidence was largely not disputed. That began to change once the use of DNA evidence became more popular with prosecutors. Soon, defense attorneys began to routinely challenge the admissibility of DNA tests.In general, two standards are used to judge the admissibility of novel scientific evidence – the “Frye standard” and the “Daubert standard.” The Frye standard originates from a 1923 case, Frye v. United States, where the court ruled that, to be admissible, scientific evidence must be “sufficiently established to have gained general acceptance in the particular field in which it belongs.
“The stricter “Daubert standard” is more recent. It was derived from the 1993 case Daubert v. Merrell Dow Pharmaceuticals. In this case, the Supreme Court went beyond the Frye standard and stated that evidence must have sufficient scientific validity and reliability to be admitted as relevant “scientific knowledge” that would “assist the trier of fact.” It is true that DNA can serve as extremely useful evidence during criminal trials.ProsAccurate evidenceThe greatest advantage of DNA profiling lies in its specificity. Even relatively minute quantities of DNA at a crime scene can yield sufficient material for analysis. Forensic scientists typically compare at least 13 markers from the DNA in two samples.
In a test with 13 markers, the probability that any two individuals would have identical profiles is estimated to be below 1 in 10 billion. Consequently, when specimens are collected properly and the procedure is performed correctly, DNA profiling is an extremely accurate way to compare a suspect’s DNA with crime scene specimens.Can exonerate/ convict people after the factDue to the biometric nature of DNA evidence, it can be used to exonerate people long after they are convicted. This pattern of verdict reversal through the use of DNA evidence has been seen many times in the past few decades.
Stuart Taylor Jr.,Senior Fellow of Governance Studies at the Brookings Institution, stated “Irrefutable DNA evidence has exonerated some 15 death-row inmates and almost 200 other men convicted of murder or rape, mostly since the late 1990s. This DNA-evidence revolution… has alerted many who support the death penalty in principle to the fallibility of the criminal-justice system and the risk of executing innocent people.” in an Nov. 17, 2007 article for the National Journal.
Alternatively, the use of DNA can be used to solve “cold cases” long after the crimes are committed. A 2010 article from The Guardian details how in 2008, a 19-year-old man from Nottingham was arrested for careless and inconsiderate driving. The police took his photograph, his fingerprints and a swab from the inside of his cheek to get his DNA profile.
This profile was flagged as a close but not perfect match to the profile of the probable killer of 16 year-old Colette Aram. Because the match was so close, and our DNA is similar to that of our family members, three years later the careless driver’s father, Paul Hutchinson, was charged with Colette Aram’s murder. He pleaded guilty and was sentenced to life imprisonment. This case becomes much more intriguing when you consider the timeline.
Colette Aram’s murder took place 5 years before the careless driver was even born. To provide context, Aram’s murder was featured in the first ever episode of Crimewatch in 1984. It is extraordinary that with the use of DNA profiles, this case was able to be successfully closed after so many years, serving justice and providing closure to the family.Unfortunately, not everything relating to the use of DNA in court is positive.Cons”CSI effect”DNA evidence is only one of many types of evidence jurors should take into account when considering a case. TV shows like “CSI” and “Forensic Files” may have popularized forensic science to the point where some jurors have unrealistic expectations of DNA analysis and give it more weight than other types of evidence. This phenomenon is called the “CSI effect.
” This effect can prove extremely dangerous if jurors regard DNA evidence as infallible, leading them to wrongfully commit a suspect only because of what the DNA test shows. DNA testing also presents ethical problems, especially when samples are taken of people who are not suspected of any crimes.Ethical QuestionsMore and more police are asking innocent people to give them samples of their DNA, imposing what are called DNA dragnets.They are asking hundreds, even thousands, of people for blood or saliva, in the hope of finding the one person whose DNA matches DNA left at a crime scene.
It is true that this method can work to solve crimes where no suspects can be immediately identified. But it also means that thousands of people are pressured to turn over personal identifying information to the police, or risk being seen as a suspect in the case if they refuse to be tested.BacklogsA final problem relating to DNA evidence is the substantial backlog of unanalyzed DNA samples and biological evidence from crime scenes, especially in sexual assault and murder cases. Far too often, crime scene samples wait unanalyzed in police or crime lab storage facilities.
The Department of Justice reports that timely analysis of these samples and placement into DNA databases can avert tragic results. For example, in 1995, the Florida Department of Law Enforcement linked evidence found on a rape-homicide victim to a convicted rapist’s DNA profile just eight days before he was scheduled for parole. Had he been released prior to being linked to the unsolved rape-homicide, he may very well have raped or murdered againConclusionThe utility and power of DNA as a tool to convict criminals or exonerate suspects has been greatly supported by the careful legal reviews and stringent quality assurance guidelines that have been developed over the course of nearly twenty years.
As the technology continues to advance, we must ensure that DNA analysis serves justice and protects the public.