Require that citizens obtain a "firearm license" in order to purchase firearms and ammunition. This would entail that citizens take and pass a written and range test to demonstrate proficiency in safety, gun laws, and how to operate the various types of firearms available to the public. The process would be similar to that of obtaining a driver's license and must be renewed every year.
Merge the NCIS and DMV databases so that only one ID card would be needed, so that retailers could quickly scan the person's card for validity. Any felonies on the person's record would invalidate his license and cause to have it revoked indefinitely.