Which of the following is not a requirement for a successful undercover investigation?

In the context of a successful undercover investigation, developing necessary evidence for prosecution, while important in the broader scope of criminal investigations, is not considered a foundational requirement for the undercover phase itself. Instead, the primary focus during that phase is on the abilities and preparations that facilitate the undercover work.

Having a qualified investigator is crucial because it ensures that the person conducting the investigation has the necessary skills, knowledge, and experience to navigate the complexities of undercover work safely and effectively. A plausible cover story is also vital, as it helps maintain the investigator’s secrecy and credibility, allowing them to blend into their environment without arousing suspicion. An effective control scheme is necessary to ensure that the undercover investigator can communicate and seek assistance if needed while minimizing exposure to danger.

Ultimately, while evidence collection is a goal of an investigation, the specific requirements for the undercover phase center around operational readiness and the investigator's ability to operate undetected. Thus, 'developing necessary evidence for prosecution' is not a foundational requirement for conducting the undercover investigation itself.