The FBI investigates all bank robberies. A very common event is for a wit to see a vehicle but no plates. Let’s say a green jeep.
And so, the gman will look into all green Jeep Cherokees in the area. He doesn’t work a regular beat, and he can spend that time.
He may call all local dealerships. “Hello, this is Tom Jones FBI, how ya doing today? Listen, did you sell any green jeeps in the last year? Great! Could you send me that list? My fax number is…. Thanks for your cooperation.”
The skills of an agent are not different from…..… an ordinary cop. The cases are bigger, that’s all. They chase a different class of criminal. As usual, there’s a muscle end and a brains end. The muscle likes executing. search warrants and raids, while the pure investigator works the brains side.
Because of the nature of the cases they work, feds are big on appeals to the public for information. They have the resources to chase down hundreds of tips and leads.
The feds are infamous for one thing: stealing cases.
Whoever solves the case gets the credit. They’ll listen to all the info that local PDs have to give, while offering little of their own. THIS IS TRUE EVEN TODAY, despite 911. Everybody competes for promotions and funds.
This ties into something else. There are federal, state and local prosecutors.
Everybody’s got to eat. Who do we give the case to? More cases, more convictions, more prestige and money. 3 levels of pigs eating out of the same slop-bucket.
Cops find criminals in their jurisdictions for prosecutors to charge. The American just-us system is a HUGE racket. Jails need to be built, guards hired, social workers, victim rights advocates, lawyers, appeals courts, and so on.