DNA has been used in criminal cases to tie the accused to the scene of the crime. This relatively new technological advancement has been helpful for prosecutors as it is difficult to “fake” a DNA test. Your DNA generally does not change throughout your life.
Any time there is a bodily fluid or cell, DNA can usually be found, which makes it easier to link the accused with materials located at or near a crime scene. The accuracy is astounding, and it has been shown to be more effective than even fingerprint matching. Nonetheless, DNA matching is not 100% accurate, despite popular belief, and a DNA mismatch could mean the conviction of an innocent person.
One of the things that California criminal defense attorneys frequently want to know when they are defending situations that involve DNA testing is how the test was performed. That information, however, has been notoriously difficult to obtain. San Diego Judge Orders Information Production Regarding DNA Testing On March 28, 2018, a San Diego Superior Court Judge, Charles G. Rogers, ordered that a defendant should have access to the information requested regarding how a DNA test was performed. The defendant wanted the computer software source code, the user manual, and other materials that were used in the DNA analysis computer program used by a third-party that the District Attorney’s Office utilizes to conduct DNA testing.
The DA is balking at the order, arguing that the information requested is private, confidential business information that cannot be shared with others. The information is also copyrighted, and the DA is prohibited by a non-disclosure agreement with the company from sharing that information.
The criminal defense attorney involved argues that these factors should not inhibit his client’s ability to present his defense, and the judge agreed. While the DA is expected to appeal the order, this could be a big step for California criminal defense attorneys and their clients.
The program, STRmix, tested a bloody glove that was found near a murder scene. The testing result concluded that the defendant’s DNA was on the glove, placing him near the scene of the crime.
The program uses an algorithm to interpret DNA testing samples from multiple people. It runs millions of calculations to determine the statistical likelihood that a particular DNA is included in the mixed sample provided, in this case, the bloody glove. This process is known as “probabilistic genotyping,” and it is becoming more and more commonly used throughout the country. Even the FBI and U.S. Army labs use this type of software.
The accused involved in the San Diego case was initially tried in 2010. DNA testing concluded that he was a contributor to the DNA mixture found on the bloody gloves. However, the guidelines that were used to reach that conclusion were changed after that, and the revised result came back as “inconclusive.” His conviction was then thrown out, and they set a new trial. The DNA conflict is now center stage in his new proceeding.
Although DNA testing is generally very accurate, it is not right all of the time. Testing methods can be questionable, which can make the results of a test unreliable. If you have been accused of a crime that may involve DNA testing, you need a criminal defense attorney that understands and can deal with these often-complex issues. Contact Okabe & Haushalter for more information.