Hold shooter enablers accountable

I want to pass a law requiring three people to vouch for a person wanting to buy any firearm. If that firearm is used in a crime, the legal result is applied not only to the gunman, but also to the three people who vouched for that person. So when (not if) we have the next gun massacre in our country, we begin punishing the people who aided the gun result. I want this applied in retrospect to all gun crimes in the past 20 years. The second amendment nutjobs want their guns? Fine. Let's get them into prison for crimes they aided.