Which type of evidence at a crime scene may contain DNA?

Biological evidence is the type of evidence at a crime scene that may contain DNA because it includes any bodily fluids, tissues, or other biological materials that can provide genetic information. Examples include blood, saliva, hair, and skin cells, all of which can be collected and analyzed to identify individuals through DNA profiling. DNA from biological evidence is particularly valuable because it can uniquely identify a person with a high degree of certainty, making it a crucial component in forensic investigations.

In contrast, physical evidence may encompass items like weapons or fingerprints but does not inherently contain biological materials that could yield DNA. Trace evidence refers to small quantities of material that can transfer from one location or object to another but similarly does not guarantee the presence of DNA. Finally, documentary evidence involves written or recorded information and does not include biological samples that could contain DNA.