Isn't it far fetched to believe that Frank wouldn't

faggot OP here, WAS working, not wasn't

>>86411528
1. Billy's uncle Jackie was one of Frank's most trusted associates.
2. Billy failed out of the police academy officially.
3. Billy was arrested and spent some time in jail.
4. Billy was doing shitty drug deals with Uncle Eddie from Grounded for Life and getting into fights with dagos from Providence.
5. Costello tortured Billy and Billy didn't admit to being a cop

In short, there were multiple reasons why Frank would choose to believe Billy

>>86411662
I suppose

I guess I don't see Frank "In the old days I would've just killed everyone" Costello not seeing that he would be a prime candidate for a plant

Frank was an FBI informant himself. His brother was involved in Massachusetts politics. He didn't care.

>>86411839
they went through a shitload of work so he'd have to be pretty fuckin paranoid

>>86412177
Oh yeah this too. Frank was the biggest rat of everyone.

>>86411528

The main reason Frank shouldn't have trusted him is because Leo played it as if he was going to shit himself from fear throughout the entire film.

heh

Frank didn't give a shit anymore, one of the main themes in the movienis showing how sloppy he gets and how he's already ratting to the FBI himself.
Hell he might have kept him on in hopes of getting a plea deal.

>>86411662
didn't they find an eavesdrop in the pool? billy threw it there