The motive was unclear for the attack, which occurred at a time of heightened concern in France about knife attacks in schools.
Mental Health Issue
Not the choice of weapons
The cause is not the weapon, yet with firearms the same person would be able to hurt more people.
Or a truck(car), bomb, baseball bat, machete, poison…
Bombs and cars possibly. Poison with very favorable conditions maybe. Bats and machetes no.
Bomb are illegal, of course you can create bombs with materials legally acquired. Still way more complex than shooting, the Columbine shooters’ bombs failed to explode, their guns did not.
Cars can be deadly as well but they have way more important alternative uses to firearms. They also are not as commonly used to attack people as guns where both are readily available.
