If the issue is simply poor grades or attendance, a meeting with a teacher is all that's needed. If there's some disciplinary problems, then a meeting with the vice-principal may be in order during school hours. Threats of a fine or criminal prosecution and/or a police record is absurd.

A note home warning of a three day expulsion for the kid if they don't turn up for their arranged meeting (the third time) would be sufficient. Parents are just as busy as teachers, and it's almost impossible for some to get to school grounds before 5 pm.

I don't like how threats are being used to enforce minor regulations. This drives people in the other direction and will end up in an even more fragmented society.