At six years old,I wouldn't be checking my childs bag.
I would be packing every single item.
If he was going to pack something he shouldn't,I would expect it to be an extra bar of chocolate.Not knives.
Must be me who thinks a six year old taking knives to school is "Unusual".
How does a six year old manage to get a couple of large knives into school without his parents noticing?
If he deliberately hid them then didn't he obviously know what he was doing was wrong?
Why cutting someones head off?
What if he had fallen out with one of his mates at playtime?
Big knives...