What is the primary focus of a private investigator's investigation?

The primary focus of a private investigator's investigation is to gather evidence for clients. This involves systematically collecting and analyzing information to support a client's needs, whether they relate to civil cases, criminal matters, or personal issues. Private investigators employ various techniques, including surveillance, interviewing witnesses, and researching public records, to compile substantial evidence that can be presented in court or used to resolve disputes.

While monitoring a subject's daily life is sometimes a facet of an investigation, it is typically just one method of gathering evidence. The core objective remains the collection and organization of relevant information to assist clients. Providing legal advice and engaging in legal disputes fall outside the scope of a private investigator’s role; those functions are typically reserved for licensed attorneys. Therefore, the definitive purpose of a private investigator is to gather evidence, which underscores the correct answer in this context.