If you've worked with a private investigator before, you're probably pretty knowledgeable on the role and limits of a PI. For those who have never worked with a private investigator, it's important to know the difference between a detective and an investigator. Often, private investigators have previous experience in law enforcement, but that doesn't mean they can do all of the same things. PI's largely focus on personal, legal, financial, and other related matters. While they are sometimes employed by law enforcement, that doesn't mean that they are law enforcement.