What is the definition of physical evidence in forensic science?

Physical evidence in forensic science refers to any tangible object that can be collected from a crime scene or relevant location that helps to establish facts related to a criminal investigation. This can include items such as fingerprints, hair, blood, weapons, and other materials that link a suspect to a crime or confirm details about the incident. The significance of physical evidence lies in its ability to provide objective data that can support or contradict testimonies and claims made during the investigation and trial processes.

The other options do not align with the definition of physical evidence. Witness statements, while important in legal settings, are not classified as physical evidence because they consist of verbal accounts rather than tangible items. Theories explaining criminal behavior fall under psychological or sociological analysis, not forensic science. Techniques used in crime-scene investigations, while crucial for collecting evidence, refer to the methodologies employed rather than the evidence itself. Thus, choice A accurately captures the essence of what physical evidence is in the context of forensic science.