When Does DNA Evidence Fail?
Introduction DNA (Deoxyribonucleic Acid) is considered one of the most powerful tools in modern forensic science. It can identify individuals, link suspects to crime scenes, and even exonerate innocent people. Because of its accuracy, DNA evidence is often seen as infallible. However, in reality, DNA can fail under certain conditions. DNA evidence is not always available, usable, or reliable. This blog explains when, how, and why DNA evidence fails, especially in forensic investigations. 1. Effect of High Temperature on DNA High temperature is one of the biggest enemies of DNA. Extreme heat causes DNA degradation Hydrogen bonds between base pairs break The DNA strands fragment into small pieces Examples: Burnt bodies Fire accident crime scenes Explosions or bomb blasts 👉 In such cases, DNA may be too damaged to analyze, making identification difficult or impossible. 2. Effect of Time (Old or Degraded Samples) DNA does not last forever. Over time, DNA naturally breaks down Enzyme...