A private investigator or private detective is a person who secretly follows and observes persons in public places for the purpose of witnessing behavior and collecting evidence of any illegal or improper activities (photos, videos, etc.). During the divorce process a spouse who suspects their spouse of cheating (adultery) or other improper or illegal behavior may hire a private investigator to follow or “tail” the other spouse.

In Idaho, private investigators are not licensed at the state level, as Idaho does not have a state-wide licensing requirement for private investigators. However, some local jurisdictions within Idaho may have their own regulations and licensing requirements, so it is important for private investigators to check with local city or county governments where they plan to operate. When hired during a divorce process to gather evidence of adultery or other improper behavior, private investigators must adhere to the law, which includes not trespassing on private property, not recording individuals in places where there is an expectation of privacy without consent, and not engaging in harassment or other illegal activities. Evidence gathered legally by a private investigator can potentially be used in court proceedings, including divorce cases. It is advisable for individuals considering hiring a private investigator to consult with an attorney to ensure that any investigation is conducted within the bounds of the law and that the evidence obtained will be admissible in court.