Muslim Brothers Djohar and Tamerlan Tsarnaev Bombed Boston Marathon
Muhammad commanded his followers to violently subjugate non-Muslims (Qur'an 9:29), and to kill those who "make mischief" in a Muslim land (5:33). Also, according to Muhammad, those who financially support soldiers are equally responsibility for the deeds of the soldiers (Sunan Ibn Majah 2759). Since U.S. tax payers financially support the U.S. soldiers who are fighting in Muslim lands (e.g., Afghanistan), U.S. citizens are viable targets for terrorists. Hence, by blowing up spectators at the Boston Marathon, Muslim brothers Djohar and Tamerlan Tsarnaev were simply following the teachings of Muhammad.
Here is Djohar's VK social media page, where he identifies himself as a Muslim.