http://dailycaller.com/2013/05/01/new-boston-suspects-drove-car-with-terrorista-1-license-plates/
http://www.dailymail.co.uk/news/article-2317493/Saudi-Arabian-ambassador-Washington-DENIES-nation-warned-United-States-Tamerlan-Tsarnaev-2012.html
They were so fiendishly clever about covering up their tracks, you can see why the Obama Administration was fooled.