DNA profiling technologies have had a considerable impact on how forensic science and criminal investigation have been understood, carried out, and regulated in the last 25 years. Current methods of forensic DNA profiling (known also as DNA fingerprinting and DNA typing), based on Polymerase Chain Reaction (PCR) amplifications of a varying number of Short Tandem Repeat (STR) loci found at different locations on the human genome, are regularly described as constituting the “gold standard for identification” in contemporary society. Prior to the implementation of PCR based extraction and amplification methods in the 1990’s, the initial uses of DNA fingerprinting (based on Multiple and Single Locus Probes) were largely confined to reactive forensic casework. DNA testing is typically presented – not only in the public, but also in the legal domain as almost failsafe way to identify individuals and to match traces found at crime scenes with a suspect’s profile. In addition, as a result of growing transnational mobility and the global use of information and communication technologies, crime and crime prevention issues are increasingly being addressed by agencies and policy actors beyond the nation state.
At a time when criminal justice systems in Europe and North America increasingly seek to utilize the epistemic authority of a variety of sciences in support of the apprehension and prosecution of suspects and offenders, genetic science and recombinant DNA technology are often singled out for particular approbation. In the European context, the so-called Pru¨m regime obliges law enforcement authorities in all EU countries to render their forensic DNA databases searchable for other member states. Member states which do not have centralized forensic DNA databases are legally obliged to establish them in the near future.
In sum, the importance of forensic DNA databasing will continue to increase in the political and public arenas across Europe. The existing literature on DNA profiling and databasing from social-scientific and socio-legal studies has so far been mainly focused on the situation in the UK and the US. 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. While the majority of DNA doesn’t differ from human to human, some 3 million base pairs of DNA vary from person to person. In human cells, DNA is tightly wrapped into 23 pairs of chromosomes. One member of each chromosomal pair comes from your mother, and the other comes from your father. In other words, your DNA is a combination of your mother’s and your father’s DNA. Unless you have an identical twin, your DNA is unique to you. This is what makes DNA evidence so valuable in investigations it’s almost impossible for someone else to have DNA that is identical to yours.
But catching a criminal using DNA evidence is not quite as easy as “CSI” makes it seem. “CSI: Crime Scene Investigation” routinely draws more than 20 million viewers per episode, making it one of television’s greatest successes. The show’s popularity owes a great deal to the writers and actors who bring the stories to life. But another intriguing element is the cutting-edge technology used by the Las Vegas crime lab trying to solve crimes. DNA profiling for the prosecution might say that the DNA profile created from the crime-scene evidence has a 4-to-5 probability (or 80 percent chance) of matching the DNA profile created from the defendant’s sample.
Saying that the probability of the match is 80 percent, however, is not the same thing as saying that the probability of the accused person’s guilt is 80 percent. RFLP analysis was in part discontinued because of the possibility for error. The risk of a coincidental match using RFLP is 1 in 100 billion. However, in laboratory settings, this risk is probably higher because technicians may misread similar patterns as identical or otherwise perform the analysis incorrectly. In 2002 a study of accuracy of DNA laboratories in the United States conducted by the University of Texas showed that 1 in 100 profiles may give a false result. any DNA profile can give a false result if it is contaminated. Although there have been no documented cases of a laboratory worker intentionally contaminating a DNA sample, DNA samples have been contaminated or even faked by criminals in order to avoid prosecution. In 1992, Dr.
John Schneeberger was accused of raping one of his patients while she was sedated. A DNA profile was created using the sample that he left on the victim. A profile from a sample of his blood did not match the crime-scene sample, and the case was closed. The victim persisted, and eventually Dr. Schneeberger was convicted after additional DNA samples showed a match. He was able to avoid the initial match by implanting a drain in his arm filled with another man’s blood and an anticoagulant, and skillfully getting the technician who drew his blood to do so from that spot. How many rights does an individual have in any given society? That’s the primary question that must be answered in the subject of DNA profiling. Although this practice can help to find a higher level of justice, it may also invade on the rights of every private citizen.
Law enforcement agencies today are asking people to voluntarily give them DNA so that they can be excluded from criminal investigations. If someone refuses a volunteer donation, there is almost always an automatic assumption of guilt. There are many Pros about DNA profiling, taking a sample of DNA can be as simple as swabbing the inside of a cheek with a cotton swab. Compare this to the older methods of obtaining DNA that came from blood samples, and there is less pain and discomfort involved with the practice.
DNA profiling can also be used to determine who the parent of a child are. In the past, paternity cases were often settled based on a propensity of evidence about who the parent was supposed to be. Thanks to this technology, parents can be confirmed so that proper court awards can be handed out.
It can reduce the amount of wrongful convictions that occur. In any given year, about a dozen people are exonerated from a guilty conviction for a serious crime because their DNA did not match the DNA of the suspect committed the crime. According to FBI research, since DNA profiling became standard in 1989, the primary suspect in sexual assault cases has been excluded in 1 out of every 4 investigations. There are also many cons of DNA profiling, there is a lack of privacy. You have to let someone into your intimate circle for them to be able to take a proper DNA sample. This means that there is no way to maintain your overall privacy during this procedure. The data could be hacked, we’ve already seen what can happen when millions of user profiles are hacked from retail store and payment information is stolen.
Now imagine what could happen if a database that held store DNA profiles was hacked and used for criminal gain. It would take identity theft to a whole new level. It can easily be manipulated Because the average person sees DNA as a 100% irrefutable science for identification, that data can be manipulated by someone to make others that something has happened when it really has not. No practice is 100% perfect. Whenever humans are involved, there is a possibility for error.
DNA profiling has helped to free a lot of innocent people over the years and that’s a great thing. What we need to ask ourselves is this: how far do we want DNA profiling to go? By weighing the pros and cons of it, we can find a compromise that will work for all of us.The unique temperature at which a given fragment of DNA unwinds could be used to speed up identification of suspects at police stations and allow hair samples and other evidence to be profiled at the scene of the crime.Forensic scientists create a DNA profile of an individual from a sample of saliva or hair by extracting the DNA and making multiple copies of the short tandem repeats, or STRs, at 13 signature regions on the human genome. STRs are typically two to five base pairs long and are repeated many times head to tail, as in GACT-GACT-GACT. What differs between individuals, and is key to a DNA fingerprint, is the number of these repeats at the key points, and hence the length of the strands.
When you look at all 13 points together, each person’s profile will be different.The length of a DNA strand is measured by drawing the sample through a polymer gel using a high voltage the longer the strand, the slower it moves through the gel. But this process usually takes about a day and has to be done by a forensic scientist using a large, delicate machine, so scene-of-the-crime analysis is not possible.That can delay investigations as suspects are often released before the DNA results come through, says Stuart Hyde, who heads DNA operations for the Association of Chief Police Officers in the UK. “The sooner you can get a DNA profile done, the sooner you can take action.” Tom Brown, a chemist at the University of Southampton, UK, is working with London-based DNA analysis company LGC to develop a technique that instead uses the temperature at which the STRs unwind to deduce their length. The process can be carried out in one tube, is potentially faster and does not require forensic expertise, he says. Brown created a synthetic stretch of DNA and tagged it with a fluorescent molecule that emits a bright green colour when it binds to another strand of DNA, but only a weak colour when unbound.
He then mixed the labelled synthetic strand with the STR strands. By heating and cooling the mixture, he forced the STRs to first unwind and then to rebind to the fluorescently labelled strands instead of their original partners. When they were heated again slowly, he recorded the temperature at which green light faded, signifying that the double strand had separated.
As the chemical forces holding the two strands together depend on the length of the strands, longer strands unwind at higher temperatures. An STR with seven repeats unwinds at 53 degrees, one with eight at 57 degrees and one with nine at 60 degrees. However, as STR strands get longer, the temperatures at which they unwind are very close together and hence difficult to resolve. Brown hopes to space these temperatures further apart. By adding nitrogen-containing chemical groups to bases at the 16th position and higher on the synthetic strand, he can increase the contribution made by each base to the attractive forces holding the two strands together. In 2015, National Institute of Standards and Technology chemist Shin Muramoto found that ridges on a fingerprint release a substance known as palmitic acid at a predictable rate, allowing investigators to determine when prints were laid down and whether they’re temporally relevant to a crime.
And at the University of Albany, chemist Jan Halámek recently published a method to determine the sex of the person who left a print based on proportions of amino acids found in skin oils. One of the most significant developments in forensics the advent of DNA profiling in the 1980s also continues to advance. More than just a means of tying a suspect to a crime scene, genetic information can reveal clues about a culprit’s appearance through a process called DNA phenotyping. Indiana University Purdue University Indianapolis geneticist Susan Walsh has successfully predicted eye and hair color based on genetic markers known as single nucleotide polymorphisms (SNPs), and Pennsylvania State University anthropologist Mark Shriver has used SNPs to make predictive digital mugshots. DNA phenotyping has met some skepticism, which is important given an individual’s freedom may be on the line; overconfidence and pseudoscience both have a long and tragic history in forensics. Exhibit A: Galton, the father of fingerprinting, falsely claimed that criminal tendencies could be detected in the faces of people who physically resembled known lawbreakers. Last year, a study released by the President’s Council of Advisors on Science and Technology raised a fresh round of concerns, finding inadequate scientific support for standard techniques ranging from ballistics testing to blood spatter analysis.
However, forensic science is also a powerful technique to scrutinize itself, as researchers discover and correct past inadequacies. Studying the reasons why blood spatter can be misleading, Loyola University Maryland biologist David Rivers recently observed that the blood was sometimes spread by flies. So in a move that would surely have impressed medieval China’s CSI, Rivers developed a spray that could distinguish bug-borne spatter by detecting fly gut enzymes in bloodstains. Check out some other cutting-edge ways researchers are advancing established investigation methods. in the 1990’s, the initial uses of DNA fingerprinting (based on Multiple and Single Locus Probes) were largely confined to reactive forensic casework.
In this modality of use, laboratories directly compared DNA profiles obtained from biological material left at crime scenes with those taken from individuals already charged with involvement in the specific serious criminal offense under investigation. However, the subsequent ability to construct digital representations of profiles and store them in continuously searchable computerised databases has made possible a vastly expanded role for DNA profiling in many criminal investigations. In particular, this technology is increasingly applied deceptively rather than reactively. In other words, it shapes an inquiry by identifying potential suspects from the start rather than merely supporting their incrimination or exoneration after they have been nominated for attention by other more traditional – and often very protracted – forms of investigative practice. In addition, a series of laboratory improvements to enable the reliable extraction of genetic material from a wider range of samples in varying conditions has meant that forensic laboratories can more easily generate DNA profiles to facilitate the investigation and prosecution of a larger number of crime types. Sometimes (as in cold case reviews) such methods may succeed when other forms of forensic or witness evidence has proved insufficient or unreliable in helping bring offenders to justice for crimes committed some years earlier.
In sum, the importance of forensic DNA databasing will continue to increase in the political and public arenas across Europe. The existing literature on DNA profiling and databasing from social-scientific and socio-legal studies perspectives has so far been mainly focused on the situation in the UK and the US (for exceptions, see the contributions in Hindmarsh and Prainsack 2010, Machado and Prainsack 2012). Technology and society (STS) scholars Sheila Jasanoff and Michael Lynch were among those who pioneered the field by putting practices and institutions at the interface of law and forensic science on the agenda of social science and STS research. Simon Cole’s seminal work on the history of criminal identification techniques and technologies provided the first social science account of the emergence and practice of the “science” of fingerprinting.
Prior to the implementation of PCR based extraction and amplification methods Accordingly, policy makers, criminal investigators, and legal professionals have been able to depict a series of benefits already derived or potentially derivable from the increasingly routine and inexpensive use of this technology and its expanding applications. These benefits include: the potential to make speedy and robust suspected offender identifications through automated profile comparisons in centralized criminal justice databases; the ability to confidently eliminate innocent suspects from investigations; the increased likelihood of generating reliable and persuasive evidence for use in court; a reduction in the cost of many investigations; the likely deterrent effect of DNA databasing on potential criminal offenders; and a possible increase in public confidence in policing and in the wider judicial process. However, the spread of forensic DNA profiling and databasing has also prompted a wide range of concerns about problems that may arise from the storage of tissue samples (especially those taken from individuals without consent) and the proliferating uses of genetic information by the police. As a result, in jurisdictions where forensic DNA databases have been introduced, a range of critical commentaries have emerged which have sought to counter claims for the effectiveness of DNA-aided investigations with assertions of potentially problematic ethical and social consequences of their uses. Such commentaries have focused on: the threat to the bodily integrity of citizens who are subject to the forced and non-consensual sampling of their genetic material; the intrusion and denigration of privacy rights caused by the storage and use of tissue samples; the potential for the future misuse of such samples held in state and privately owned laboratories; the prospect of long term bio-surveillance occasioned by the storage of genetic information in police databases and biological samples in forensic laboratories; and the possibility for the deceptive use of DNA forensic evidence in police investigations and criminal prosecutions.
Everyone’s DNA profile should be included in a database, according to Robert Williamson and Ronnie Duncan in their Commentary “DNA testing for all.¨ This approach has much to recommend it to the police and the prosecution, but it will do little to increase the accuracy of any prosecution in terms of justice. In Correspondence David Ehrenfeld invokes a 1907 detective story to comment on problems of classical fingerprinting still relevant today. If such problems are still arising after nearly 100 years, how much more likely are problems with a universal DNA-profile database only a few years after the introduction of this technology? One such problem concerns depositing DNA by touch when items are handled. It is possible to detect such handling successfully”, a fact already used in a criminal case in Canada Who can remember every item that he or she has touched for longer than one minute in the past week? When the knife you used in a restaurant is identified as a murder weapon, what is going to be your defence? There are major problems associated with a universal DNA profile database. Would foreign visitors be profiled on entry? What happens if the person who matches the crime-scene DNA profile has an alibi at a distant place? The database proposal places a reverse onus on accused people to show their innocence, even when there is no other evidence to link them to the crime.
What are the error rates for each step in the DNA-profiling procedure? Because the probability of a duplicate match is so low, Bayesian theory suggests that when there is no other evidence, error is likely to be a higher probability than a correct match. Although the safeguards Williamson and Duncan suggest are implementable in the United Kingdom, Australia and other industrialized countries, they are impossible in countries such as South Africa because the cost of independent forensic laboratories is prohibitive. In many countries, most sample collection is done by police officers, not scene of crime scientists, and a lack of resources makes independent testing impossible. Samples from suspects, even in the United Kingdom, are taken at police stations.
DNA profiling can be a huge help to the law enforcement, but can also be a huge problem with ethics and protection of people and their DNA. Of course, computerized DNA databases are no more immune to hacking than any other database. So having a country wide data base for DNA wouldn’t be good, it could be hacked and they would have access to everyone’s DNA.