When packaging wet evidence like bloodstains, what must be done first?

When handling wet evidence, such as bloodstains, allowing it to dry is crucial. This step is essential because packaging wet evidence without drying it can create a suitable environment for microbial growth, which may degrade the sample and compromise its integrity. Drying also helps to preserve the evidence for analysis and prevent contamination. Once the evidence is adequately dried, it can then be carefully sealed and stored appropriately to maintain its condition for future analysis or legal proceedings. This practice follows the principle that maintaining the chain of custody and the condition of evidence is critical in criminal investigations.