Here's an idea for 'stricter control', which doesn't only involve a psychological screening.
1. Obtaining a license
a: The applicant shall be of legal age
b: The applicant shall have no prior convictions
c: The applicant shall pass an extended background check, similar to that required to obtain a 'classified' rating
d: The applicant shall pass a theoretical and practical training course; the course shall be of a duration of no less than 20 weeks
e. The training shall be specific to the type of weapon the applicant seeks permission to carry, e.g. hunting rifle or handgun. If an applicant wishes to obtain a license for both hunting rifle and handgun, he or she shall pass the relevant training for both types
e: Following successful passing of the above, the applicant shall be eligible for obtaining a license to owning a firearm, in accordance with the training they have received
f: The applicant shall freely agree to being eligible for continued auditing of fitness to carry a firearm
g: The applicant shall agree to annual re-qualification of firearm permit
h: The applicant is solely responsible for all costs incurred during the application and training period
2. Obtaining a firearm
a: No firearm holding a capacity of more than 5 rounds may be obtained by a private individual
b: The applicant shall prove secure weapons storage is available, but at their place of residence, during transport and in temporary accommodation. Said storage shall be made available for unannounced inspections by the authorities at any time
c: The weapon(s) shall be securely stored at all times, including during transportation and whilst in temporary accommodation. Only exception is during hunts, where the applicant may carry the weapon unsecured on his person. Under no circumstances, however, may the weapon be left unsecured during rest periods (e.g. you cannot leave your weapon outside a locked container at night if you're camping)
d: Weapons may only be sold from a licensed store. Prospective owners shall, following an approved order of a weapon, endure a waiting time of no less than 1 month for delivery
e: Retailers of weapons shall ensure customers are fully compliant with all requirements. Failure to do so shall make the eligible for civil and criminal prosecution
f: Only licensed retailers may sell weapons; the sale of weapons between private individuals is strictly forbidden
g: All weapon and ammunition purchases shall be stored in a central database
h. No prospective gun owner shall be allowed to own more weapons than is reasonably necessary
3. Gun and ammunition manufacturers
a: No firearm may be manufactured or sold to private individuals holding a capacity of more than 5 rounds
b: All guns and ammunition shall have unique identifiers, making it possible to link a weapon or a fired round back to the original owner
c: All weapons shall be fitted with DNA safety mechanisms, ensuring only the registered owner may fire them
d: No weapons may be sold to private individuals which can in any way, shape or form to made function in an automatic or semi-automatic fashion
e: Gun and ammunition manufacturers are eligible for civil and criminal prosecution if their products can in any way be modified to make them illegal
There you go, free of charge!
1e - What do you discuss for 20 weeks that would have an impact on people that commit mass murders?
1g - Does re-qualification require another 20 week class?
2a - So a law abiding nutjob can only kill 5 people before reloading? I bet the families of those 5 victims would argue that this law is just as ineffective as the current one.
2b - In violation of the 4th Amendment.
2h - Who defines "reasonable?"
3a - See 2a
3c - Give a determined person time and it'll be disabled and the entire system made ineffective at preventing what you're trying to do. You're better off not bothering.
3d - So you're down to bolt action rifles and muzzle loaders being legal?
3e - Your plan would lose all backing if this was part of a proposed law. There is performing due diligence to design a safe product but making a manufacture responsible for someone else's modifications isn't going to hold water.
Then again we could always deal with the mental health and social issues that lead up to these people committing these acts.....