you are fixated on the tool. determined psycho/sociopaths will use whatever tool is available. take away tools that are legal and responsibly owned by 99.9999% of  gun owners, and you will not stop one determined criminal from carrying out his compulsion.  

There is no reason why democrats should be anti-gun. We drove many middle America democrats out of the party to become Reagan Republicans and vote against their own self-interest, in part, because our Vietnam protest and reaction to political assassinations of the 60's. led to an unstoppable zeal to recreate the party into a rainbow coalition. We became pacifists who hired out our war-making to professionalized military of the poor and people of color. We live in cities  where we depend on police to provide the illusion of security and we are shocked, shocked! when violence shatters the delusion.  And of course we feel entitled to legislate against everything we don't like.  Why can't we take responsibility for our own security?