Private investigators have been used for many years to undertake investigations. Unlike those attached to police departments, they're hired by lawyers and ordinary citizens. Often called PIs or inquiry agents, they serve many areas like the ones listed below.
The internet can be used to search for a lot of things, including checking on somebody's background. However, information is not complete and many times inaccurate so it doesn't serve the purpose especially in a legal case where validity is critical.
Unlike the internet, PIs conduct interviews, visit places and go through records to find the history of a person. Results are accurate since cross checks are performed so even if a person were to lie about his background, there's a good chance an investigator will find the truth.
All crime case is overseen by law enforcement and professionals like lab analysts, medical examiners, and forensic specialists. If a person is the victim of a crime and isn't fully satisfied with the findings of the police and the professionals mentioned above, he can hire a private investigator.
The term PI today is linked mainly to investigating infidelity. Reality shows are responsible for propelling them into the limelight.
While having someone followed is not a very tasteful idea, sometimes it's the only solution for the injured party. For example, a husband suspects his wife is cheating on him. He has no way of finding the truth as it's his word against hers. With the help of a PI, he can learn whether his fears are valid.
Surveillance is done to gather evidence of a crime, record a person's presence in a site, and keep an eye on activities happening in and around a building.
When conducting surveillance, PIs have the responsibility of not infringing on a person's privacy. Current laws are strict and they need to stay within legal limits. Most good PIs do, however, so clients have little to worry about.
People may need to be located for a number of reasons, chief among them being because they've run away from legal obligations. When this happens, clients are on the losing end especially when a lot of money is at stake. What PIs do is conduct interviews, rely on informers, conduct surveillance, and perform background checks to find a missing person.