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New Study Could Change How Touch DNA Is Used in Criminal Cases

Posted on in Criminal Defense
Wisconsin defense attorney, Wisconsin criminal lawyer, defendant rightsBeginning in 1986, human DNA testing began to revolutionize the criminal justice system by providing law enforcement and the courts with far better identification evidence by which to prove either the innocence or guilt of a suspect. However, DNA evidence and matches are not infallible; and a recent study suggests that we must, once again, consider just how valid such evidence against an individual may be. Touch DNA Sensitivity Today DNA is found within every chromosome and cell of our bodies. It can also be transferred from skin to a surface; this is known as “touch DNA.”  Pulled from everything from guns to doorknobs, touch DNA is one of the most widely used forms of DNA evidence in criminal investigations. Initially, large samples were needed for testing, but technology has advanced so much that now we only need a small trace. This has both pros and cons. On the positive side, we can detect the presence of human DNA much more easily. On the negative side — as highlighted by the recent stud y— sampling may actually pick up traces of DNA through second person transfer and the risk of contamination and false match is greater. All It Takes Is a Handshake Two graduate students from the University of Indianapolis recently paired up with the university’s director of Molecular Anthropology Laboratory to determine if they could pick up traces of touch DNA from someone that had never touched an item (secondary DNA). Subjects from the study were instructed to shake hands for two minutes. Then, one was asked to touch a test knife. The other subject never came into contact with the test knife. In 85 percent of the samples, researchers were able to pick up traces of DNA from individuals who had never come into contact with the test knives. It was transferred during the handshake and was left behind by the handler. The implications of this is startling and disturbing, as innocent people could be charged with crimes based on an erroneous match Changes in How Forensic Evidence Is Viewed Forensic scientists still do not completely understand how DNA transfers from a person to an object. Secondary transfer may not be the same during brief contact, or when touching rough objects, or when dealing with certain materials. However, this new study and the potential for cross-contamination and false positives are bound to change how DNA is used in criminal cases. It may also be quite important for those who have already been convicted based on DNA matches and other types of forensic evidence.  For further reading on the need to improve various types of forensic evidence analyses utilized by law enforcement, see the 2009 study by the National Academy of Sciences, “Strengthening Forensic Science in the United States: A Path Forward.” Facing Criminal Charges? You Need Knowledgeable and Aggressive Legal Help When facing an investigation or criminal charges, you need an attorney that is willing to carefully examine the evidence to prepare a solid defense case. When dealing with forensic evidence like DNA, you need experienced defense counsel, who are knowledgeable both in the law and the science. Our team is comprised of highly-skilled litigators, some of whom have worked on the police force, as criminal prosecutors, justice department investigators and have science backgrounds.  Schedule your consultation with one of our knowledgeable and experienced Milwaukee criminal defense attorneys by calling 414-271-1440 today.


https//ncjrs.gov/pdffiles1/nij/grants/228091.pdf http://fox59.com/2015/11/10/new-study-says-your-dna-can-show-up-at-a-crime-scene-even-if-you-were-never-there/ https://uindy.edu/2015/10/28/study-raises-question-about-dna-evidence http://innocenceproject.org/causes-wrongful-conviction/unvalidated-or-improper-forensic-science
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