Which of the following is a common investigative technique used by Private Investigators?

Surveillance is a foundational technique utilized by private investigators to gather information and evidence discreetly. This method involves observing an individual’s activities, interactions, and behaviors in real-time, allowing investigators to collect data necessary for their cases. The effectiveness of surveillance lies in its ability to produce firsthand accounts of an individual's actions without direct confrontation, often yielding crucial insights into suspected activities or relationships.

In contrast, psychological profiling typically falls outside the conventional scope of a private investigator's work and is more associated with criminal psychology and law enforcement. Database encryption and network testing are technical processes related to information technology and cybersecurity, rather than investigative techniques employed by private investigators in the field. Understanding these distinctions is essential, as it underlines the varied skill sets and methods that are relevant to different professional domains.