Which aspect of a crime scene is crucial for collecting DNA evidence?

The timely preservation of biological evidence is crucial for collecting DNA evidence because DNA can degrade over time or be contaminated if not handled properly. Biological samples, such as blood, saliva, or other bodily fluids, are highly sensitive and can be affected by environmental factors, including temperature and exposure to sunlight, which may compromise their integrity.

Promptly securing and preserving these samples is essential to ensure that they remain viable for analysis. This includes using proper storage methods, like refrigeration or freezing, and ensuring that samples are collected using sterile techniques to prevent cross-contamination. If biological evidence is not preserved in a timely manner, it may lead to a loss of critical DNA information that could be pivotal in solving a case or identifying a suspect. Thus, this aspect is fundamental in forensic investigations involving DNA.