The job of a private investigator is to gather information for businesses and individuals. They work on many different types of cases and frequently are found assisting attorneys, businesses and the public with a variety of legal, financial and personal problems. Most private investigators are trained to perform functions like surveillance, research and interviewing . They also have access to computer databases and searches, that the public does not , which allow them to quickly obtain large amounts of information. Because of the nature of their work, they also can be called to testify in court .