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DNA Evidence Can Be Wrong

Jul 31, 2017 by Mike McKneely in Criminal Defense

The use of DNA testing has undoubtedly revolutionized how criminal cases are investigated and prosecuted. Widely regarded as irrefutable evidence, traces of your genetic information can connect you to a criminal investigation, and later convince a jury of your guilt. If your DNA matches blood, hair, or saliva found at a crime scene or on a victim, your defense will require a great deal of extra effort. Fortunately, DNA evidence can be wrong. A skilled Fresno criminal defense attorney may be able to point to issues with the DNA testing and have it removed from the prosecutor’s case.

If you’ve been charged with a crime based on possible DNA evidence, don’t delay and contact an experienced criminal defense attorney with Michael McKneely, Criminal Defense Lawyer at (559) 443-7442 for a free and confidential consultation.

How Does DNA Testing Work?

All humans share 99.9% of their DNA, but we all have some genetic traits that set us apart. By analyzing your DNA, it’s possible to isolate the genetic markers that make you unique. At crime scenes, investigators will collect samples of anything that might contain the perpetrator’s DNA. Once the suspected perpetrator’s DNA profile is obtained, law enforcement looks for matches in publically available records.

When Does DNA Testing Fail?

DNA testing is incredibly accurate when done properly. The only real possibility of two people sharing the same DNA is in the case of identical twins. Yet there are situations where DNA testing in criminal cases leads to the arrest and prosecution of innocent people:

  • Bad sample collected at the scene–According to Erin E. Murphy, a professor at the New York University School of Law, samples containing DNA mixtures of three or more people often produce a flawed genetic profile. For example, a sample collected from a cash register, a door, or any other surface that might contain a variety of genetic material, may not provide a reliable genetic picture of the suspect. If this kind of sample is being used to connect you with a crime, your lawyer may be able to challenge it.
  • Improper lab procedures–In busy jurisdictions, crime labs handle hundreds and sometimes thousands of samples at the same time. Rigorous procedures are needed to ensure there isn’t a mix-up. Your lawyer will obtain all the documentation relating to your sample to ensure that it was properly collected, stored, labeled, and analyzed. It’s possible that your sample was tainted. In 2013, for example, it emerged that more than 800 rape kits sent to the New York City medical examiner’s office had been handled by an unqualified technician.

What’s the Future of DNA Testing?

California has recently adopted a new method of DNA testing that raises important ethical concerns. Familial searching is a method through which investigators increase the chances of catching culprits by searching for their family members. When investigators find a relative of the person whose DNA was found at the crime scene, they’re often able to quickly identify and apprehend the actual suspect.

Familial searching, which led to the arrest of the serial killer known as the “Grim Sleeper” in Los Angeles, is being criticized for ensnaring innocent people in criminal investigations and disproportionately affecting people of color. African Americans are overrepresented in DNA databases because they are disproportionately arrested. So, when the police run DNA searches, they are at a higher chance of singling out families of color.

Michael McKneely Can Help

The issue of whether familial searching violates the constitution has not yet come before the courts, but it is likely to occur as the police continue using this technique to find suspects. If you’ve been contacted by law enforcement about an investigation, or if you’ve been charged with a crime, you should contact a Fresno criminal defense lawyer immediately.

A case involving DNA evidence requires your lawyer to act promptly and decisively. The sooner the possible issues with the sample are revealed, the higher your chances of avoiding a conviction.

Call Michael McKneely, Criminal Defense Lawyer today at (559) 443-7442 or online for a free and confidential case consultation.



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