Which of the following is an example of firsthand knowledge for an officer?

Firsthand knowledge refers to information that is directly observed or experienced by an individual, in this case, a police officer. When an officer makes observations at the scene, they are witnessing events, behaviors, or situations directly with their own senses. This type of knowledge is considered the most reliable, as it is based on the officer's direct experience.

In contrast, details from a police report, witness accounts from bystanders, and information relayed from dispatch are all forms of secondhand knowledge. They rely on what others have seen, reported, or communicated rather than the officer's own observations. Therefore, firsthand knowledge is characterized by direct involvement and observation of an event, which is why the observations made by the officer at the scene serve as the best example in this context.