This is not an EZ discussion, but it is one we need to have.

The mass shootings are horrible, and I believe that we, as a society, have a moral responsibility to take preventative action. Now, what we need is to define a meaningful course of action.

Help me out here: considering recent history which includes mass shootings where the law forbids firearms, what do we do? 

Help me to define a law or an action that would have prevented this most recent shooting, or one of the earlier ones. *How* do we make sure the crazy, sick, angry and lost people don't get a gun (or a knife, or a bat, or a rock -- FBI statistics show that more people are murdered with a knife in the U.S. than with a gun)? 

Norway has some of the world's most strict firearm laws, yet Anders Behring Breivik was able to bypass them all, obtain weapons, and kill many youngsters. There have been mass shootings in Finland and other non-U.S. lands. In fact, when corrected for population density, The top 5 countries for mass shootings per capita all have “restrictive” gun policies--the U.S. is seventh in that list when corrected for population density. 

Perhaps it is a culture of violence (movies, games, music) and a lack of respect for human life (capital punishment, easy abortions) that is to blame?