Former brother-in-law Elmirza Khozhugov explains Tamerlan Tsarnaev’s grievances to the New York Times:

He was angry that the world pictures Islam as a violent religion.

So he blew up an eight-year old boy and a couple of hundred other Americans.

And now the media are full of stories about how the Tsarnaevs were all-American kids and “beautiful, beautiful boys” and maybe it was the boxing or the Ben Affleck movies or the classical music but, whatever it was, it was nothing to do with Islam. Nothing whatever.

So I guess it worked.