How Common is DNA Evidence?

Posted On: October 21st, 2014 by Bradley J. Groene

It’s the time of year when fall shows are starting back up, and if you watch any TV at all, you probably can name at least several popular crime-solving shows. These shows are great for making people aware of their rights when arrested, which is why I appreciate them, but they are not always an accurate portrayal of the criminal justice system.

One problem that I find commonly in these crime shows is that they depend strongly on DNA evidence; however, DNA evidence isn’t always as common as it seems on crime shows. DNA may be left behind by criminals, but in order to use it during trials, the evidence must be uncontaminated and found by investigators. Although hair, blood and other DNA evidence are often found at crime scenes, other evidence, such as forensic evidence, eyewitness testimony and other circumstantial evidence, is just as important, if not more important, in building or defending a criminal case.

DNA Evidence Used In Less than 25 Percent of Criminal Cases

According to a UCLA study conducted in 2010, less than 40 percent of criminal cases have any relevant biological evidence that can be used. This evidence is used to build a case against a defendant even less often. DNA evidence is presented to the judge or jury in less than one-fourth of criminal cases. This is true for several reasons.

In many cases, perpetrators of crimes use gloves and other protective gear. This means that there may be no DNA evidence that would tie a criminal to a case for the police to find. Furthermore, evidence may be cleaned up afterwards. Even if some remains, the evidence could be damaged in some way.

In fact, even when DNA evidence is found, officers must prove that it is directly related to the carrying out of the crime. Just because DNA evidence tying a person to a crime is found in a particular location does not make that person a criminal. At many public places, there is simply too much DNA evidence to use any of it. Thousands of hairs could be found at a mall at any given time. DNA evidence does not automatically prove much to do with the case. If an assault occurs in a public place, finding a cigarette butt with the defendant’s saliva or other DNA evidence cannot be proven directly relevant to the crime at hand.

DNA evidence does not automatically prove the guilt of any defendant. A good criminal attorney knows the pitfalls of some DNA evidence and knows when it should be excluded. I often petition judges presiding over my clients’ cases to exclude evidence that is irrelevant or improperly gained. Just because police have DNA evidence that they say proves your guilt does not mean your case is lost.

If you have been accused of a crime, you need to have an experienced defense attorney to contest the evidence. DNA alone is not enough for a conviction. You need a Cincinnati criminal defense lawyer who you can trust. Call Brad Groene at Luftman, Heck & Associates today at (513) 338-1890 for a free consultation on your case.