Dzhokhar Tsarnaev is accused of using explosives-filled pressure cookers as bombs . The FBI says the brothers used a homemade explosive device to carry out their Boston Marathon bombing on April 15, killing three people and injuring more than 260 others. The term `` WMD '' is often used to refer to nuclear , biological and chemical arms .
Dzhokhar Tsarnaev is accused of using explosives-filled pressure cookers as bombs . He is charged with `` using and conspiring to use a weapon of mass destruction '' ( WMD ) Claims Saddam Hussein was stockpiling WMDs formed part of the argument for the Iraq War . The term `` WMD '' is often used to refer to nuclear , biological and chemical arms .