Law enforcement officers and investigators sometimes gather deoxyribonucleic acid (‘DNA’) evidence from crime scenes to solve a crime by linking criminal activity to alleged offenders. They can also use DNA evidence to eliminate persons of interest as potential defendants. Unfortunately, DNA is not always reliable and is sometimes unfairly presented by prosecutors as absolute proof of a defendant’s guilt.
If you have questions about DNA evidence and how it may impact you in a criminal case, attorneys at Vinas & Graham, PLLC, can discuss your questions and concerns. They understand how forensic science can be used in criminal cases and how DNA collection can impact the outcome of your case.
Human Error In Collecting And Preserving DNA
Prosecutors often present DNA evidence as reliable and absolute proof that a defendant committed a crime. However, defense attorneys can examine how the DNA evidence was collected and hire experts to help determine if the prosecutor’s evidence is valid and reliable.
Many issues can lead to unreliable DNA evidence, such as errors made due to lack of training or sloppy and incompetent evidence collection and processing. DNA contamination can occur when the DNA evidence is not handled correctly, and another person’s DNA or other contaminates are mixed in with the evidence sample.
After evidence is collected, law enforcement officers and others who process the DNA are required to comply with chain of custody procedures and evidence log requirements. When prosecutors cannot establish credible evidence handling and chain of custody, defendants can argue that the evidence was tampered with or is tainted and should not be used at trial.
DNA Can Be Used To Prove Innocence
DNA evidence does not always have to be used to prove that a defendant is guilty and can sometimes be used to prove a defendant’s innocence. For example, DNA evidence can be used to exclude the defendant as a suspect by demonstrating that the DNA discovered at the crime scene does not match the defendant’s DNA.
Forensic experts are also sometimes able to link evidence to another person who was the likely perpetrator. DNA may be matched to another suspect in the case or someone else whose DNA is in the Combined DNA Index System (CODIS), a national DNA database. Criminal charges may be dismissed when DNA is matched to another person, and a defendant is excluded as a suspect.
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Establishing Proof Of DNA Does Not Necessarily Demonstrate Guilt
As mentioned above, DNA evidence is often presented by prosecutors as unwavering proof of a defendant’s guilt. Fortunately, DNA evidence does not always prove guilt, and additional evidence may be required for a conviction. Defendants might have legitimate reasons and explanations for their DNA being discovered during an investigation.
For example, if a defendant was a friend or acquaintance of the victim, that might explain why the defendant’s DNA was at the victim’s house or in their car. Even if a defendant cannot explain how or why their DNA was at the scene of a crime, they may have an irrefutable alibi to prove their innocence.
False Testimony And Other Misconduct Related To DNA Evidence
Recently, the reliability of evidence in hundreds and possibly thousands of local Texas criminal cases has been questioned due to what has been identified as a DNA analyst’s false testimony. Therefore, forensic expert testimony should never be assumed to be reliable and valid without thoroughly examining the evidence collected and the evidence handling practices.
Houston criminal defense attorney Joe Vinas, from Vinas & Graham, PLLC, is close to one of the cases in question in regards to the DNA analyst’s false testimony and says, “When you’re an expert in a court of law, you’re given a lot of deference and trust in that position. And when you abuse that trust, that really just undermines the entire system”.
A judge might throw out DNA evidence if the police collected the evidence during an illegal search and seizure. For example, if the police searched your car or home in violation of your constitutional rights and collected DNA or other evidence during the search, a judge may rule that the evidence cannot be used against you at trial.
Unfortunately, evidence planting or tampering sometimes occurs, and such conduct can be challenging to uncover. Falsifying DNA evidence can lead to the wrongful conviction of an innocent person. This is why it is critical to have professionals review the investigation and evidence collection process to discover any potential misconduct.
Call For A Consultation With A DNA Defense Attorney
If you are facing charges that involve DNA results, you need a reputable criminal defense attorney to review your case and the DNA evidence. So, call 713-229-9992 or reach out online for a confidential consultation with a Houston DNA defense attorney at Vinas & Graham, PLLC. They know how DNA evidence can impact a criminal case and how to best defend their clients in these criminal matters.
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