Which is an example of physical evidence?

Physical evidence refers to tangible items that can be collected and analyzed to help establish facts or prove elements of a crime. DNA samples qualify as physical evidence because they are biological materials that can be collected from a crime scene or a suspect, providing concrete information that can link an individual to a crime.

Physical evidence plays a critical role in investigations as it can provide objective data, which is less susceptible to bias compared to testimonial evidence, such as witness statements or a detective's theory. DNA analysis can serve to confirm or exclude individuals as suspects, making it invaluable in criminal proceedings.

In contrast, the other options represent forms of evidence that do not have a physical presence and cannot be collected or analyzed in the same way. Witness statements and police reports are important for understanding events and actions but rely on subjective recall. A detective's theory is a conceptual interpretation that proposes a possible explanation of the events surrounding a case but lacks the tangible basis that physical evidence like DNA samples provides.