Amusement parks across the US reinstate chaperone policies to address unruly behavior.

Knott's Berry Farm has reinstated its chaperone policy for anyone 15 or younger after 4 p.m. The chaperone must be at least 21 years old, can accompany a maximum of ten people, must remain in the park during the visit and be available by phone. The park says there has been an increase in "inappropriate behavior" among teens.