Earlier this year, the director of a forensic toxicology lab filed a lawsuit against New York City. Marina Stajic, who spent nearly 30 years in her role at the medical examiner's office, claims that she and her supervisors disagreed about whether a new DNA testing technique is truly accurate.
According to The New York Times, this new technique is known as "low copy number DNA analysis." It is currently being used by scientists in a number of different fields. Among other things, it is used to develop criminal profiles.
The greatest advantage to this new method is that it only takes a few fragments of DNA to form a complete picture. However, the fact that it only uses a tiny amount of DNA is also its greatest drawback. When only a few molecules are involved in the test, any type of contamination can result in dramatically wrong results. Here are a few potential problems:
- Contaminated equipment. An invisible speck of dandruff from a lab worker is all it could take to yield inaccurate results.
- DNA from more than one person. Low copy number DNA analysis can pick up traces from all the individuals who recently handled an object. In fact, research shows that it's even possible to transfer DNA residue from person to person - like sharing a cold virus - so that traces end up on objects that you've never touched at all.
- Incorrect profiles. When too few DNA molecules are present, they may not replicate correctly. This means that the final genetic picture is skewed.
Of course, researchers are constantly working on safeguards to reduce the risk of wrong results. However, the fact remains that no DNA test is guaranteed to be 100 percent accurate. Innocent people may still face criminal charges and convictions. That's one reason that hiring a skilled criminal defense lawyer is so important. He or she can work to protect you from the effects of questionable DNA testing.