When collecting physical evidence, what is the proper way to handle blood evidence?

Handling blood evidence properly is critical to preserving its integrity for forensic analysis. Sealing it in an airtight container is the correct method because this prevents contamination and degradation of the sample. Blood can decompose quickly when exposed to air and moisture, which can compromise its viability for testing and analysis.

Using an airtight container ensures that the evidence is protected from environmental factors, such as humidity and temperature fluctuations, that could alter its composition. The ideal containers for blood evidence typically are made from materials that do not react with blood or allow moisture in, such as certain plastics or metal containers designed for biological evidence.

In contrast, storing blood in a glass jar can pose a risk of breakage and may not provide the best protection from contamination. Drying blood completely before packaging can also lead to its decomposition and makes it unsuitable for certain analyses, which require it to be in a liquid state. Leaving blood exposed to air would essentially lead to its rapid deterioration and contamination, rendering it useless for legal and investigative purposes.