Police can interview students in school without parental permission, but must stop if a student asks for a parent to be present. Police must only notify a parent if the child is being removed from the custody of the school to the custody of the police.
SAN FRANCISCO EXCEPTION: under an agreement between SFUSD and SFPD, there must be a reasonable attempt to notify the parent and allow them to come to the school before a student is interviewed by police. Same rules for change of custody apply.