The scenarios you describe are rare. Inner city thugs make up the lions share of murders committed with firearms.
The way to stop those is a mandatory sentence of say thirty years for a crime committed with a firearm and the death penalty for murders committed with a firearm.
Stop penalizing legal gun owners because they aren't the problem.
Wrong. The majority of gun deaths (6 in 10) are suicide, by "responsible" gun owners. Gun deaths are down significantly.
Obviously we need to get the guns out of the hands of registered owners who own them and shouldn't.
And since guns used in other deaths are primarily stolen, we need to tighten laws to keep registered, so-called responsible gun owners from letting their guns get stolen.
Gun Homicide Rate Down 49% Since 1993 Peak; Public Unaware | Pew Research Center?s Social & Demographic Trends Project