Which of the following is a form of evidence commonly found at a crime scene?

Cellular phones are indeed a common form of evidence found at crime scenes. They can hold significant data that can provide insights into criminal activities, such as call logs, text messages, photos, and location data, which can be pivotal in establishing timelines and connecting suspects or victims. The digital footprint left on a cellular phone can lead to critical information that may corroborate other pieces of evidence or reveal new leads in an investigation.

In contrast, witness statements, while valuable, come from individuals and can vary in reliability and detail. Testimonial evidence is also based on human accounts that may be subject to bias or memory limitations. Police reports are produced after initial investigations and summarize findings, but they do not typically originate at the crime scene itself. Therefore, while all of these types of evidence hold importance in investigations, cellular phones stand out as a direct source of tangible data often accessed right at the crime scene.