Sleepers by Lorenzo Carcaterra

An unforgettable true story of
friendship, loyalty and revenge. They were four boys who shared everything –
the laughter and bruises of an impoverished upbringing in New York’s West
Side. Then one of their pranks misfired – a man nearly died and they were
sent away to a reformatory school. They they suffered the worst abuse the
guards could inflict on them. They were forever scarred by their experiences.
Eleven years later: two of them became killers for the mob. They met the
ringleader of the guards who had abused them – and shot him dead in front of
several witnesses. No one thought they would see the outside of a prison
again – but the four friends banded together once more and in one last,
audacious stand brought their own vengeance to the courtroom.