Abstract
The DNA analysis becomes a cornerstone in contemporary forensic sciences. DNA sequencing technologies are powerful tools that enrich molecular sciences in the past based on Sanger sequencing and continue to glowing these sciences based on Next Generation Sequencing (NGS) technologies. NGS has impressive potential to flourish and increase the molecular applications in forensic sciences by jumping over the pitfalls of the conventional method of sequencing. The main advantages of NGS compared to conventional method are their higher throughput (parallel sequencing which will help in reducing DNA backlogs), lower cost and short run time with high resolution of genetic data. These advantages will help in solving several challenges that
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Forensic DNA analysis continues to advance owing to development of new technologies. Addition of new informative markers to existing panel can improve discrimination power and accuracy. Next Generation Sequencing technologies (NGS) can bring new offers. Firstly, higher throughput which help in reducing significant DNA backlog in forensic laboratories. Secondly, parallel analysis became possible with NGS which can greatly improve the throughput (one run to all markers) and discrimination power. Thirdly, the clonal aspect of NGS platforms can also offer great advancement such as greater sensitivity for mixture analyses which considered as challenging samples. Lastly, with decreasing the cost and miniaturized equipment, it will become possible to do whole genome sequencing on a bench-top DNA sequencer. That will revolutionize the field of forensic DNA analysis. Recently, the impressive advances of sequencing technologies have enabled a lot of new applications. Therefore, this review will discuss the applications of NGS in forensic sciences as a simplified guide for future forensics studies and …show more content…
Although there is a significant progress in solving some technical challenges associated with forensic STR profiling. Even with these technical advances, important challenges remain for the use of genetic approaches in human forensic investigations (Kayser and de Knijff 2011). Traditional capillary electrophoresis (CE) based STR typing rely on the detection of DNA fragment size. Therefore, alleles of similar length but of different sequences cannot be distinguished. Consequently, STR mutations in complex paternity cases often cannot be resolved with traditional CE-based STR analysis (Yang, Xie et al. 2014). An additional challenge for forensic DNA tests is the analysis of complex DNA mixtures comprising DNA from more than one person. Contemporary analyses of mixed DNA samples often yield low detection rates (Hu, Cong et al.
The murder of JonBenet Ramsey is a crime that received national attention and was seen on nightly news stations and talk shows across the country. All of this attention made the case extremely controversial (Saferstein, 2015). It is now over twenty years since the murder occurred and the case still remains unsolved. The development of DNA evidence has played a critical role in the course of this arduous investigation (Saferstein, 2015). Crucial mistakes were made from the very start of the investigation by police and then by the district attorney, Mary Lacy (Saferstein, 2015).
But in Adnan Syed case this was not done. If the DNA test was
The Solid sequencing platform, produced by Technologies/Applied Biosystems (ABI), performs sequencing by ligation method. Similar like the Roche 454 library preparation, genomic double strand DNA were sheared into small pieces and ligated with two types of adatptors P1 and P2 on two ends. One end with P1 adaptor binds onto the surface of the magnetic bead and emulsion PCR takes place to amplify single nucleotide fragment. Then the oil was washed out and four fluorescent labeled di-bases probes were added into the beads mixture. By matching the 1st and 2nd position of the template by di-base probes, fluorescence was detected and the extra tail with fluorescent probe is cleaved out.
Again, if this crime was committed when we knew more about DNA, the defendant would probably have been found
The leader of this group, named Deirdre, said that scanning extra objects for DNA is important, ”When I talked to DNA experts that they were saying, ‘Yeah, I mean, if you swab that and get some skin cells or saliva and it’s just random, you get no hit on anybody, well then it neither here nor there.’ But they were saying, ‘but if put it in and you get a hit on a serial killer… well now you got enough to charge and convict somebody.’ So what you call relevant and irrelevant you can only do once you have a test result” (111). Deirdre likes to test anything that could possibly lead them to another suspect in the crime. Not everyone in the detective business is, however, not like her.
Alan Crotzer—DNA Exoneration In the United States, there have been a total of 321 DNA exonerations to date, with twenty of these exonerees having served time on death row (“The Innocence Project,” n.d.). Alan Crotzer was not one of these twenty, however he was sentenced to 130 years in prison for a crime that he didn’t commit. Charged and convicted of sexual battery, kidnapping, burglary, aggravated assault, robbery, and attempted robbery, it wasn’t until 24.5 years later, on January 23, 2006, that Crotzer was released from prison after post-conviction DNA testing proved his innocence (“The Innocence Project,” n.d.).
What if the DNA was tampered with or contaminated? DNA testing is not always reliable and this issue is evident in a large number of investigations. One well known incident of this occurring is the Josiah Sutton rape case- "In 2004, Josiah Sutton was exonerated after serving four and a half years of a 25-year sentence for a rape he did not commit. Sutton's conviction was the result of a mistaken identification and faulty scientific testing performed by the Houston police laboratory.
Today, the FBI has DNA records of more than 5 million convicted offenders in the database CODIS, or Combined DNA Index System. However, DNA fingerprinting has limitations: it is limited to directly connecting crimes to felons already in CODIS, has high risk of contamination, does not look at familial records, and only analyzes short pieces of DNA. With the advent of more affordable and high resolution genetic technologies after The Human Genome Project, over 35 million people have submitted their DNA to the largest direct-to-consumer genetic companies. Two companies, FamilyTreeDNA and GEDmatch, also allow law enforcement access to their databases. Thus, beginning investigative genetic genealogy, a new method of forensic investigation not only with higher resolution DNA information than DNA fingerprinting but also the capability of finding a suspect from distant relatives.
Although, in our lab report, suspect ones DNA matched the crime scene when cut with enzyme one, this can be explained by how closely related the two suspects are. Therefore two enzymes were used to cut the DNA; the suspect has to match both. Moreover, the limitation to DNA fingerprinting is, if a person were to have an identical twin. This is because identical twins have the same DNA because they come from the same egg. If a suspect’s DNA matched that of the one being tested, and they had an identical twin, a farther investigation would need to be done.
In King, Justice Kennedy referred to the invention of DNA technology as “one of the most significant scientific advancements of our era.” This statement has been criticized, but the impact of DNA technology has been significant. Currently, forensic analysts can use “junk” DNA to identify a person with near certainty. Law enforcement can collect a person’s DNA through saliva. The sample is then uploaded to CODIS, a national network of DNA databases.
Destiny Johnson LSTD 502 Criminal Law January 10, 2016 A. Research Paper Topic: Wrongful Convictions B. Law abiding citizens should not be wrongfully convicted of a crime that they did not commit. Deoxyribonucleic Acid (DNA) was first used to aid a criminal investigation by Professor Jeffreys in 1986 for rapes/murders that occurred in the United Kingdom. The first DNA exoneration took place in 1989. Prior to DNA testing there were hundreds of wrongful convictions.
One of the most accurate methods of connecting a suspect with a crime is through the use of DNA analysis. Even if no fingerprints are left behind at a robbery, for instance, a single strand of hair or skin cell from the thief can be used to positively identify a suspect. Conversely, if a suspect’s DNA does not match samples procured from a crime scene, the use of so-called “genetic fingerprinting” can exonerate, or clear, them. Concern over the issue of wrongful convictions, coupled with a sense of greater trust in DNA analysis over other, more conventional methods of prosecution, such as eyewitness testimony, has led some to call for mandatory DNA testing before any person begins serving a sentence for a serious crime, as well as
The police took hair and saliva samples from Gary in 1987 but unfortunately due to DNA not being well developed yet he was released with no further questioning. (Gish, 2017) The DNA content of biological samples can be quite high depending on the type of sample and how well you acquire them. Depending on local conditions which they were found and especially on the length of time between deposition and collection. Gladly, in this case, the hair and saliva sample which saliva contains 100-1 500 ng/swab and a hair plucked (with root) contains 1-750 ng/root, was well collected and stored, making possible to solve this crime.
Today, practical methods of using fingerprinting are extremely wide. In 1995, the size of the FBI fingerprint card archive contained over 200 million items, and archive size was increasing at the rate of 30,000 to 50,000 new cards per day [2]. Forensic science was the very first and most important area of its application, which still remains. The rapid development of computer technology has made it possible to create such fingerprint scanners that can be installed on laptops, cell phones, flash drives,
DNA in forensic science The majority of cells making up the human body are diploid cells carrying identical DNA, with the exception of haploid gametes and red blood cells. Several types of biological evidence such as blood and hair are commonly used in forensic science, which is the scientific study of evidence for crime scene investigations and other legal matters. Forensic science is used for the purpose of DNA analysis, this is the analysis of DNA samples to determine if it came from a particular individual. DNA analysis is done by obtaining DNA samples from an individual; next, a large sample of DNA is produced from amplified selected sequences from the DNA collected.