When I say "knife attacks" I don't mean person a stabs person b. I'm talking about gang a runs through a crowded area stabbing and slashing everyone in their path. Dozens die, hundreds are injured - nobody knows where it's coming from because screams come from all directions.
My point is, criminals will commit crimes - regardless of how many laws are written to stop them. Someone who knows what they're doing can spend $100 in Home Depot and walk out with enough bomb making components to take out an entire school. Saudis did it with airplanes, the Boston Marathon was attacked with pressure cookers, Timothy McVeigh did it with fertilizer, arson, blunt force, exsanguination, asphyxiation, poison, electrocution, sabotage - I could go on and on.
If someone wants you dead, and they want it bad enough - they'll kill you. Tools are everywhere, made of everything. If you think it takes a gun to kill a person, you aren't firing on all neurons.