The group anonymous is saying that the shooter is a veteran who suffered from PTSD, and warned of his plans several weeks ago on 9gag. he was also a well educated neuroscience phd student at Colorado.

https://twitter.com/YourAnonNews

Article on the premeditation on 9gag is found here: http://www.blottr.com/breaking-news/...r-9gag-website. Apparently the user submitting the memes user name was JamesHolmes124.