Whatever the author(Lorenzo Carcaterra) says, he published it as a novel so his actions spoke louder than his words. Apparently he made a lot of enemies after publishing the book, including Bobby Moresco, Tommy's brother according to this article. "Yesterday, I spoke to Bobby Moresco, now an accomplished screenwriter, who had told me back then that Carcaterra had obviously appropriated the story of Moresco's dead brother and made it into "Sleepers."
"I remember all of it. I stand by everything I said 10 years ago. He lied," Moresco said. "Do I resent it? Yeah. Tell him the next time I see him I'll smack him in the face. Better yet, ask him why no one from the neighborhood remembers him?" Bobby Moresco said when I wrote the story.
https://www.google.com/amp/s/www.fo...rothers-personal-life-may-be-exposed.amp