Sounds like CYA to me by the school district. It is mandatory for the children to attend school, and I assume because of that the school district is responsible for the children's safety until they are delivered back to their parents/custodians. If I am right on this, then the school district faces massive fines by the parents/custodians. Elementary schools we have visited have very good security and attendance verification. Sounds like a major screw up by the school system, starting with the little boy's teacher.
Where am I wrong on this?
We used to live in a large city, before we had children. For a long time, we kept receiving automated messages from a school stating simply: "Your son or daughter was not in school today. Please call the school to confirm your child's absence." The name of the school was given, but no number.
After receiving these calls again and again, I looked up the number to the school and called. I told them we had no children but were receiving these calls. The office worker said, "Just ignore them. The calls should stop eventually."
I said: But, in the meantime, a student has been missing school, and the parent doesn't know. Apparently, the school has the wrong number, and it's my number. Can they trace the student through my number?
The woman said: No, there's no way to trace it. Just ignore the calls.
The recorded calls kept coming for months. Finally, a teacher called. When I told her what had been happening, she was surprised, but the calls stopped then.
That's why, when we had small children, I decided to see how our local school would deal with an absence. ;-)
I hope and pray they find this little boy alive and well - perhaps, as someone else suggested, with a noncustodial parent or relative.