I believe we have sufficient laws on the books regarding guns because:
It is illegal for a convicted felon to posses a firearm.
It is illegal to allow a felon access to a firearm.
It is illegal for a person dishonorably discharged from the military to posses a firearm.
It is illegal for a mentally unstable person to posses a firearm.
It is illegal for a person with past or current domestic violence action against them to posses a firearm.
It is illegal to leave a firearm where a child can access it.
It is illegal to brandish a firearm in a threatening manner.
It is illegal to use a firearm in the commission of a crime.
It is illegal to commit armed robbery.
Murder is illegal.
In most cities, discharging a firearm is illegal.
Possession of an unregistered machine gun is a Felony, punishable by 20 or more years in Federal prison.
If someone discharges a firearm in self-defense, they are already legally liable for what each bullet hits.
Criminals, by definition, do not follow the laws of society.