What is your solution to criminals that still have guns and break into people's homes or still commit mass shootings? If someone breaks into my home with a gun what is your advice?
Those who are mass shooters are common citizens like you and me who had access to a tool whose only purpose is to kill a living being. The police should have this tool. No other person needs this tool.
The solution is to either have the SCOTUS reinterpret the 2nd Amendment to what the founders intended, which was for each State to have a cache of weapons available to provide to a state militia for the protection of it's citizenry. Or, using the Constitution, remove the 2nd Amendment from the Bill of Rights.
Then, remove all guns from the populace that are not expressly regulated for hunting game such as deer, water fowl, pheasants and other licensed hunts. All persons found to have unregulated weapons would have the weapons confiscated and be fined for their violation.
Christians who are obeying Christ Jesus and God, would be the first in line to turn in their illegal arsenal and register their hunting guns with the government. Christians will stop placing their faith in their weapons and stop making guns an idol of worship and trust. Christians will obey their King and entrust their exiled life to God alone.
That's my solution. I already know that the vast majority will revolt at my solution and label me with titles like "liberal" but, I have God's Word on my side so I will stand alone if necessary.