Investigation agencies are organizations responsible for gathering information and evidence related to criminal activities or other legal matters. They often work to solve crimes, enforce laws, and ensure public safety. Examples of such agencies include the FBI in the United States and Interpol, which operates internationally to assist in cross-border investigations. These agencies employ various methods, including surveillance, interviews, and forensic analysis, to uncover facts and build cases. They collaborate with other law enforcement bodies and may also provide support in areas like cybercrime and terrorism. Their work is crucial for maintaining law and order in society.