I've written on this topic before, here and here.
With regard to this specific shooting, Germany has stricter gun control than anything found in the U.S., and they've suffered their own tragedy, almost simultaneously:
To date, the only method so far demonstrated to lessen the horror of these events is a quick response to end them. That generally involves lawful individuals shooting the criminal so he can't kill more innocents.
As seen at the right side of this blog:
"The rifle itself has no moral stature, since it has no will of its own. Naturally, it may be used by evil men for evil purposes, but there are more good men than evil, and while the latter cannot be persuaded to the path of righteousness by propaganda, they can certainly be corrected by good men with rifles." -Jeff Cooper, "The Art of the Rifle"
I've cited this before, but it bears repeating. One of the most notable quotations about gun control I've found comes from Germany's 2002 school shooting:
From the April 26, 2002 CNN article, “Mourning for victims of German school rampage”:
“The shooting came just hours before the German parliament approved a new bill tightening the country’s already strict gun controls.So note: “The danger is from illegal weapons, not legal ones, but boy we’re glad we strengthened our laws against legal firearms owners.”
“Germany already has strict laws governing the right to a gun, but experts say the country is awash with illegal weapons smuggled into the country from eastern Europe and the Balkans.
“People wanting to buy a hunting rifle must undergo checks that can last a year, while those wanting a gun for sport must be a member of a club and obtain a license from the police.
“Interior Minister Otto Schily said there was not much to be happy about on this day, but that he was glad the new tougher gun control legislation passed ‘with a broad majority in parliament.’
“‘The aim of law is to strengthen and to sharpen the (existing) laws,’ Schily said, but added the danger was from illegal weapons, not legal ones.”
It doesn't work. Let's save lives instead of passing feel good laws.