Parents, Rafael Lopez, 38, and Yadira Lopez, 30, were arrested.
When school officials found out what the boy had in his possession, they called the Riverside County Sheriff's Department right away, and deputies then went to the boy's home less than a mile away, on Pepper Drive.
When deputies got there, they say they found the boy's father in the driveway with a bunch of marijuana plants in the bed of his pickup truck. And in the back yard, they found a marijuana garden.
The Lopezes were arrested on charges of cultivation of marijuana and child endangerment.
All four kids at the home were placed in custody of Child Protective Services.
"[The boy] said that he just went into the back yard and grabbed a little pinch full of the marijuana," said Riverside County Sheriff's Deputy Josh Hephner. "He said he had brought it to school to play with it. He showed some friends at the school. While showing the friends, in the exchange, that's when the school staff saw it and brought it to our attention."