The Mistake Behind Sean Penn's Son's Arrest

Police realized Hopper Jack Penn's pills were prescription.

Tuesday we reported that the 16-year-old son of Sean Penn and Robin Wright Penn was arrested on the grounds of his posh Malibu high school. Today a strange development took place -- turns out the police made a little error.

While details about the arrest were outstanding due to Hopper's young age, we've learned that the alleged crime was drug-related. But when police sat Penn down for questioning and dealt with his parents, they found that the pills Hopper was carrying around school were in fact from a prescription bottle with the boy's name on it.

No word yet on exactly what the pills were meant to treat, but apparently all charges have been dropped and the boy is free to return to school...except now he may need to carry a permission letter from Mom along with the meds.