From the website—
Historically, the policier and the family comedy were two distinct categories. Then, in 1990, Kindergarten Cop gave us all a lesson in genre revisionism. With muscular sensitivity, Hollywood's last action hero Arnold Schwarzenegger embodies detective John Kimble, who is compelled to go undercover as a teacher of five-year-olds in order to catch a ponytailed drug dealer.
Eagle-eyed Criterion fans will note that this is an April Fool's prank, and that Criterion does it every year. But fans of Kindergarten Cop — of which I am obviously one — reserve the right to be extra delighted by this year's pick.