Detective agencies provide various investigative services, including:

1. Private Investigations: For personal matters like infidelity, background checks, and missing persons.
2. Corporate Investigations: For fraud detection, employee misconduct, and intellectual property theft.
3. Legal Investigations: Assisting law firms with case research, evidence collection, and witness interviews.
4. Surveillance: Monitoring individuals or locations to gather evidence.
5. Pre/Post Employment Investigations: Verifying candidate backgrounds or investigating former employees for misconduct.

Popular detective agencies include:

• Pinkerton: Known for corporate investigations and security solutions.
• G4S: Specializes in corporate and risk management services.
• Bureau of Investigation: Provides private and corporate investigative services across various sectors.