Corrected entry: When young Shakes asks Michael about Rizzo, he tells him that they "beat him until the was nothing left to beat." Years later Ceasar tells King Benny that his family was told Rizzo died of pneumonia. Wouldn't Rizzo's body have been returned to the family for the funeral? It would be hard to pass off a brutally beaten body for pneumonia. The Wilkinson Home would likely have been under investigation way back then.
Corrected entry: The character Shakes has the same last name as the writer of the book "Sleepers", last name being Carcaterra.
Correction: This is because the movie, being based on the book by Lorenzo Carcaterra, is about the author's own experience. Shakes Carcaterra is Lorenzo Carcaterra.
Correction: They could have lied and said he was in a fight with another inmate. There are also ways to beat someone that doesn't leave marks.