Those in favor of gun bans are arguing that the thing making the United States different is the availability of firearms and this is the reason we don't see it happening in other countries. They say that after the UK and Australia totally banned guns after similiar mass killing incidents, the problem was solved. However, truly insane people will find other ways of committing mass murder just like the Boston Marathon bombers.

There is a definite pattern to these episodes in the United States. Since the movie theatre shooting in Colorado, they've been happening on a linear schedule of about 5 to 10 months (averages out to about 6 months between events). The script is always the same as this article mentions. Many of them also happen in areas where the gun issue is politically divisive - swing states like Colorado, Florida, or Nevada, or in the blue districts of red states.