What type of container should a blood-soaked shirt be placed in for transportation to the crime lab?

Placing a blood-soaked shirt in a paper bag for transportation to the crime lab is the appropriate choice because paper allows for adequate airflow, which helps to prevent the growth of mold and bacteria that can occur when wet materials are sealed in airtight containers. This is particularly crucial for preserving the integrity of biological evidence. The moisture from the blood can be absorbed by the paper, reducing the risk of degradation. Paper also allows for contamination control and is less likely to react with the biological material, ensuring that the evidence remains uncontaminated and in its original state for testing and analysis.

In contrast, options like plastic bags can trap moisture, which creates a damp environment that is conducive to the degradation of the sample. Padded envelopes may not effectively prevent moisture accumulation and could also allow for movement of the evidence, potentially causing further damage. A cardboard box, while sturdy, does not provide the same breathable environment as paper does, so it would not be ideal for transporting a wet item like a blood-soaked shirt.