Interesting that every Muslim related mass murder in the Obama admin has had contact with the FBI prior to the attack, but let me offer an alternate view

The FBI does not want to be "punished" or criticized for "islamophobia", so they just ignore whatever evidence of jihad syndrome there is, and go on their daily business

I cant say this guy was a jihadi (I haven't looked at the claim he posted jihadi material to the web); but I do know he made contact with the FBI claiming that the army was forcing him to watch ISIS material, as Rich notes.