James brings up a good point. Correlation doesn't equal causation.
Google Insights and Google Trends reflect searches. Peaks in search are the result of people wondering, "what's this thing all about?" This is a result of a meme's usage. So a peak follows the meme's appearance.
Plus, if you filter for just the last 90 days…
http://www.google.com/insights/search/#q=girugamesh&date=today%203-m&cmpt=q
Then you can see that there was already an increase in search by March 7th, three days prior to the supposed school shooting. Honestly,
So this event is NOT what caused the meme. As for the school shooting its self:
It could be a bogus image. Or it could be that the shooter really did post about it on /b/ the day before. Either way, he fails at life. And as for people that think this is lulz, get over it. It's trollbait and nothing more.