Many criminals think they can help themselves by cooperating. Not true.
First of all, the rat usually has to reveal EVERYTHING about everybody. If he holds back anything, the deal is off and he’ll be given the full charges.
Next, he has to testify in open court. Then everyone will know he is a rat. Local, state and federal prosecutors are all going to get a piece and to pile on their own charges. He will be farmed out to anyone who can make a case; this can mean alot of time, even years, in court.
After all that, the snitch may think he is in the clear. He ratted out his buddies and now everyone knows it. Isn’t it over?
Nope. “Justice” has not been served yet. This is Murkan-style justice.
And now, the final cross. The police arrest the rat anyway, usually for something minor. He ends up in jail or prison anyway. In a country with as many laws as the USA, finding crime is not hard.
The rat dream is that they cooperate with the police, give up all the information anonymously, and then they live a normal life afterward. This is an impossible dream for all but the most important rats.