Thanks to numerous television shows, from CSI to Law and Order, more people than ever are familiar with the concept of DNA evidence.
Television shows make the process of matching someone's genetic markers with evidence left on the scene in the form of body fluids and skin cells seem precise and clear. Maybe that's why people tend to believe that DNA evidence is infallible.
Unfortunately, experts are quick to point out that science is only as reliable as the people who use it -- and not every lab technician is terribly reliable. In fact, there have been numerous incidents brought to light that have illustrated just how inaccurate DNA results can be.
Some of the most basic problems that have been uncovered are the result of nothing more than human error. Poor training, mismanaged labs and lab technicians who are eager to provide prosecutors with the evidence they want to see are a big part of why DNA evidence isn't always reliable.
However, another large issue has arisen simply because the science of DNA has become so complex. Years ago, it took a large sample of genetic material -- a large spot of blood, for example -- to give technicians what they needed to get accurate results. Now, cutting-edge technology and equipment can draw someone's genetic code out of a tiny speck of material -- a single drop of saliva or a few scattered skin cells are enough.
The problem is that so-called "trace DNA" is highly transferable. Take this example: A vagrant collapses on a city street and is transported to the hospital by an ambulance. Hours later, those same paramedics that treated the vagrant are called to the scene of a murder. Skin cells from the vagrant that transferred to the jackets of the paramedics end up mixed in with the DNA evidence collected from the victim's fingernails -- and the vagrant is charged with murder. While it sounds like a piece of far-fetched fiction, that's exactly what happened to a man in California.
If you've been accused of a violent crime and DNA evidence is involved, talk to your defense attorney about the possibility of overcoming the evidence in court. It may be more possible than you realize. You should never assume that any evidence is insurmountable -- especially if you're innocent.