When scraping dried blood for evidence, where should it be collected?

Collecting dried blood evidence on a clean piece of paper is the most appropriate method because it minimizes contamination and ensures that the evidence remains intact for analysis. A clean piece of paper can be used to gently scrape or lift the blood, preventing any additional materials or contaminants from being introduced during the collection process.

Using a plastic container or a glass vial might not be the best option for collecting dried blood, as these materials can introduce risk of contamination or degradation of the sample if not handled correctly. Additionally, collecting blood directly from a suspect's clothing can compromise the integrity of both the sample and the clothing itself since it may alter the context of the evidence or damage potential forensic details.

In summary, utilizing a clean piece of paper allows for a controlled and careful collection of dried blood evidence, maintaining its integrity for subsequent analysis and ensuring the preservation of the evidence's chain of custody.