I believe americans will never give up on their guns, sadly, so they have to at least try and control them more. School shootings do not happen in countries with strict gun control laws so there must be something to it. Also I believe there is something deeply wrong in the american culture, it's probably a lot of things so I can't pinpoint it exactly...

Plus you can add to it that some of the shootings are reported in a weird way and have all sort of conspiracy theories attached to them (sandy hooks, etc) and most of the time are used by the media to push politcal agenda or sweep other issues under the rug.