Which of the following does NOT need to be preserved as potential evidence at a sexual assault scene?

In the context of a sexual assault investigation, preserving evidence is critical to building a case. Witness statements are important, but they do not need to be physically preserved at the scene in the same way as physical evidence. Instead, witness statements can be documented through interviews that occur shortly after the incident.

On the other hand, items such as the victim's personal belongings, specimens from the victim's body, and clothing are considered essential pieces of evidence that can provide critical information regarding the assault. Personal items may contain trace evidence or serve to establish the victim's identity, while specimens from the victim's body can provide biological evidence relevant to identifying the assailant or determining the nature of the assault. Clothing can also be vital, as it may carry DNA, fibers, or other forms of trace evidence that are crucial for forensic analysis.

Therefore, while witness statements are certainly valuable to the investigation, they do not require the same level of immediate preservation as tangible items directly linked to the incident.