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How Reliable Is DNA Evidence?

DNA Evidence in Criminal Cases: Pros & Cons

No two people have the same exact DNA makeup, except for identical twins, making DNA evidence significantly important when trying to convict or exonerate defendants of a crime. It is among the most powerful and versatile tools in criminal investigations and can mean the difference between freedom and prison for a person.

Interestingly enough, only 0.1% of a person’s DNA is different from other people, as 99.9% of human DNA is the same in everyone. While this sounds like a slight difference, that 0.1% represents millions of genetic variations. That’s why suspects can be easily identified if their DNA is found at a crime scene.

Although DNA evidence seems to be the best, most reliable type of evidence, our attorneys aim to evaluate its pros and cons. Far too many defendants and juries believe DNA evidence is the top telltale sign of innocence or guilt, however, that may not be the case every single time. As such, we encourage you to review both sides of the matter below.

Benefits of DNA Evidence

  1. DNA evidence is extremely accurate, ensuring fairness in the criminal justice system.
  2. It can be stored for decades if done so properly.
  3. Police officers can turn to DNA databases if they are stuck with unidentified samples.
  4. Unidentified remains at a crime scene can be analyzed by comparison to relatives’ DNA.
  5. Can prove a person’s innocence even when there is overwhelming evidence against them.

Disadvantages of DNA Evidence

  1. DNA evidence is subject to human error, such as a lack of training, sloppy work, and cross-contamination, among other issues. A forensic expert can easily invalidate DNA evidence, rendering it useless, if they do the following to such samples:
  • Damage
  • Contaminate
  • Destroy
  • Misplace
  • Misinterpreted
  1. DNA evidence is only found in a small portion of crime scenes.
  2. DNA samples can pose privacy concerns because they expose family relationships, ancestry, and the potential for diseases. Several states allow people’s DNA samples to be used for medical research, humanitarian purposes, and identifying missing people, which can raise concerns.
  3. Innocent people can be framed for a crime if a person gets their DNA and plants it in a crime scene. For instance, strands of your hair can be easily obtained without your knowledge and placed at the scene of a crime.
  4. Jurors may have unrealistic expectations by relying solely on DNA evidence to convict or acquit someone of a crime. TV shows like CSI: Crime Scene Investigation are perceived to give people the wrong idea of how and what type of DNA evidence is obtained ― if it’s even found at a crime scene ― and presented in a trial.

Our criminal defense lawyers at Appel & Morse are former prosecutors who understand how both sides of the justice system perceive and analyze DNA evidence. Prosecutors may not interpret or present a DNA analysis report accurately or fairly and may hire lab experts who have a history of making mistakes. These are some ways DNA evidence can hurt your case, however, our attorneys can expose the prosecution’s flaws with the help of our proven network of science and medical experts.

To discuss your situation with us, please schedule a consultation online or at }!