Private investigators are hired by individuals, businesses or organizations to look into matters that may be too sensitive for public officers, may not be crimes, or that public officials simply don't have the time for.

Typically the matters being investigated are important to the client, but not conclusive enough or of a nature that is criminal enough to warrant a police investigation. Occasionally they assist law firms or attorneys in researching a case, and they may have long-term contracts with such clients. Private investigators may search through public records, track or follow subjects, trace paper trails, or use other research or reconnaissance skills to serve their clients.

Examples of some types of cases handled by private investigators can include:

• Missing persons
• Suspected financial fraud
• Domestic infidelity
• Personal background checks
  
• Computer crimes
• Copyright cases