From the title, I thought RFK weaponized the FBI against Joe Kennedy, RFK’s father. LOL!
Also, I can hardly believe that Franzese is still alive. He started spilling the beans about the mobs a couple decades ago that I can recall.
Have you seen his show on YouTube? Has his a talk show and also does interviews. He addressed your question in one of them, said after he got out of jail he was careful not to fall into any observable patterns of movement and so forth, and over time, just outlived anyone who would want him dead. He takes his Christian faith seriously now. A very interesting guy.