Remove all weapons from citizens. Or, give a high tax to citizens who possessed weapons.

For citizens who already own weapons. Enforced high tax to citizens who carry or possess weapons. Same people should go through an extensive psychiatrist evaluation. People who sells weapons to a citizen without a license should get a big fine, jail time and lose all their merchandise and the permit to sell weapons. Citizens who never own or possess weapons, will not have access to guns or any weapon. Nor permits will be given. Only the proper authorities like police, special government agencies, and army will use and carry weapons.