Which of the following can be classified as circumstantial evidence?

Circumstantial evidence is evidence that relies on an inference to connect it to a conclusion of fact, rather than direct proof of a fact. A suspect's alibi falls into this category because it does not directly prove the guilt or innocence of the individual but instead suggests that the suspect was not present at the crime scene during the time the crime was committed based on circumstances or statements provided by the suspect.

In contrast, eyewitness testimony serves as direct evidence, as it is based on a person's direct observation of an event. DNA analysis also constitutes direct evidence because it can directly link an individual to a crime through biological markers. Footprints at the scene can serve as direct physical evidence, as they provide tangible links to the suspect rather than suggesting an inference.