I've stumbled upon a nation wide scheme and i need to know how to determine the actual organization or cartel or whatever of the ring so I know how much is at stake if they find me before I can disappear, or if there's better options in this situation
Prominent media is a really good idea too.
In fact, if he decides to share information with the authorities, I'd suggest going to both media and law enforcement.
So long as he is the only person who has this knowledge, the criminals can solve their problems by killing him.
But as soon as the knowledge is shared with others, killing him no longer makes their problem go away.