The heartbreaking discovery was made in North St. Paul.
The suspect also allegedly sprayed an officer with an unknown chemical irritant.
The 6-year-old has a scar on his forehead, authorities say.
The man is also accused of threatening to kill her.
The teacher has been placed on administrative leave.
Police said he wasn't wearing a helmet.
The victim's son was arrested on probable cause homicide.
The 46-year-old was found dead with stab wounds.
It's unclear how the victim and suspect are related.