Arriving At The Scene

Watching movies related to some crime and when the police are not able to solve the mystery there is this one department who takes over the case. The FBI is the trump card that every movie use it to fulfill their plot. But remember this story is not a film script but something that really took place. The FBI arrived at the scene just the way we see it in the movies. The FBI started the investigation and the cops kept looking at them in surprise. Why was the FBI interested in two holes? The mystery of the two holes was finally being solved.