Which scenario is an example of physical evidence?

Physical evidence is defined as tangible items that can be collected and analyzed in investigations to establish facts or support findings related to an event. In this context, blood samples collected from a suspect qualify as physical evidence because they consist of a physical substance that can be examined scientifically, potentially providing concrete information regarding the suspect's involvement.

The other scenarios represent forms of testimonial or documentary evidence rather than physical evidence. Eyewitness reports consist of personal accounts and perceptions, which may not always provide reliable or objective information. A photograph of the scene serves as a visual representation that can be informative but is still not a physical object like blood samples. An officer's written account also falls under the category of documentation and subjective observation, lacking the physicality that direct evidence like blood samples provide.