What is essential for an investigator to have when setting up for surveillance?

Having a cover story is essential for an investigator when setting up for surveillance because it allows them to establish a plausible reason for their presence in the area they are monitoring. This is vital for maintaining discretion and avoiding drawing attention to themselves, which could compromise the investigation. A well-crafted cover story can help the investigator blend into their surroundings, ensuring that their actions appear natural and unremarkable to bystanders. This camouflage is crucial to successfully gathering information without alerting the subject or disrupting the unfolding events.

Other options, while they may have their uses in specific circumstances, do not provide the same level of integral support for maintaining an investigator's anonymity or unintrusive observation. For example, having a partner can be helpful but isn't always necessary, especially if the investigator is skilled in surveillance techniques. A camera is a useful tool, but having just a camera without a strategic approach to blending in would make the surveillance suspect. Lastly, public approval is not only unrealistic but also unnecessary—surveillance typically requires a level of secrecy that would preclude seeking permission from the public. Thus, the importance of a cover story stands out as a foundational element in effective surveillance operations.