It's just what the FBI does... That's what they're there for.
If a crime is committed that is a violation of local, state, and federal laws, does the FBI “take over” the investigation?
No. State and local law enforcement agencies are not subordinate to the FBI, and the FBI does not supervise or take over their investigations. Instead, the investigative resources of the FBI and state and local agencies are often pooled in a common effort to investigate and solve the cases. In fact, many task forces composed of FBI agents and state and local officers have been formed to locate fugitives and to address serious threats like terrorism and street violence.
If a crime is committed that is a violation of local, state, and federal laws, does the FBI “take over” the investigation? — FBI
- It is not a national police force; state and local law enforcement agencies are not subservient to the FBI. It's simply a different jurisdiction for different kinds of crimes.
- It doesn't "take over" cases from local agencies. If a crime partly involves FBI jurisdiction, or if it is serious enough to require FBI involvement, then the FBI forms a task force in which agents will work closely with state and local police.
- The FBI does not prosecute cases. It provides investigative information to United States attorneys, who then use that information to decide whether to prosecute.
How the FBI Works