Kelly Layne Lau and her husband, Michael Schumacher, both of Tracy, are charged with 13 counts related to the alleged abuse. The former guardian, Caren Ramirez, is charged with 10 counts.
Court documents allege the boy was beaten with a baseball bat and belt and cut with a knife.
The boy escaped from the couple's home Monday by jumping over a fence in the backyard and seeking help at a nearby gym.
