The police boss argued that the teachers at the private school were adults and had a responsibility to protect and guide their students.
The two teachers and a school driver were with 33 Form Four students comprising 11 girls and 22 boys from Naivasha Mixed High School.
Two teachers arrested after they were found drinking with their students in Ol Kalou town will face criminal charges.
Ol Kalou OCPD Wilson Kosgei said on Tuesday that police decided to add criminal charges related to child abuse, saying earlier charges of being drunk and disorderly were too lenient.