Why should plastic not be used for evidence packaging?

Plastic should not be used for evidence packaging primarily because it can cause mold growth and degrade biological evidence, particularly DNA. Biological evidence, such as blood or tissue samples, needs to be stored in breathable materials to prevent moisture accumulation. When evidence is sealed in plastic containers, any humidity present can lead to condensation, creating an ideal environment for mold and bacteria to thrive. This can compromise the integrity of the evidence and hinder its analysis and usefulness in a criminal investigation.

In contrast, packaging materials such as paper or cardboard allow for ventilation, helping to preserve the biological samples and preventing degradation. Therefore, the choice of packaging material is critical in maintaining the integrity of physical evidence in criminal cases.