What did the records show about Duane Scrod's past?

From the text:

Perplexed, Dr. Dressler pulled out the file of Duane Scrod Jr. It showed that the boy had been held back two years in elementary school and later was expelled from a public middle school for fighting with his P.E. teacher. During that scuffle, the teacher lost three teeth and the tip of his right pinkie finger, which Duane had gnawed off and consumed.