federal agents http://wamc.org en Boston bombing traced to pressure cookers packed with shrapnel; motive a mystery http://wamc.org/post/boston-bombing-traced-pressure-cookers-packed-shrapnel-motive-mystery <p>Federal agents are zeroing in on how the Boston Marathon bombing was carried out, but there's still no word on who did it and why.</p><p>An intelligence&nbsp;bulletin issued to law enforcement and released late Tuesday includes a picture of a mangled pressure cooker and a torn black bag. The FBI says evidence indicates the bomber packed a pressure cooker with explosives, nails and ball bearings and hid it in a back pack. The agency says the second bomb was in a metal container, but there isn't enough evidence to indicate that it was a pressure cooker.</p> Wed, 17 Apr 2013 12:12:09 +0000 Jaired Crofut 62439 at http://wamc.org Boston bombing traced to pressure cookers packed with shrapnel; motive a mystery