The Tsarnaev Brothers

On April 15, 2013, the Tsarnaev brothers, Dzhokhar and Tamerlan, detonated two bombs at the Boston Marathon.  Tamerlan died during a shootout in the city of  Watertown four days later.

On April 8, 2015, Dzhokhar was found guilty on 30 different counts stemming from his participation in the bombing of the marathon, the killing of a MIT police officer, a carjacking, and the subsequent shootout and detonation of bombs in Watertown.

But too many unanswered questions and conflicting evidence has led some to believe there was a cover-up.