MCOLES State Licensing Practice Exam

What is the best way to preserve a blood-soaked towel found at a crime scene?

1. Photograph it and leave it

2. Seal it in a plastic bag

3. Hang it up to dry

4. Remove it and leave it out for collection

The correct answer is: Hang it up to dry

The best practice for preserving evidence, particularly a blood-soaked towel found at a crime scene, involves preventing further contamination or degradation of the biological material. Hanging it up to dry, while it might seem like a way to preserve the evidence, is not an appropriate method. When biological evidence is left to dry, it can lead to the breakdown of the DNA contained within it, which diminishes the value of the evidence for forensic analysis. Additionally, exposing it to air can introduce other contaminants, such as dirt, bacteria, or other environmental factors that could compromise the integrity of the sample. The recommended approach is to carefully collect and package the towel in a breathable container, such as a paper bag, to allow moisture to escape while preventing contamination, rather than opting for plastic bags that can trap moisture and lead to mold growth. This method ensures that the evidence remains viable for analysis while also maintaining the chain of custody needed for legal proceedings. Proper evidence collection and preservation protocols are critical in forensics to ensure the reliability and credibility of the evidence in court.