what appears to be a circuit board. unidentified, where thaed they come from? an unidentified government official released the photos to reuters to show what is going on. that official also provided these pictures of a mangled pressure cooker. we believe that's what was housing the explosive. >> in one photo you can see what appears to be a cluster of bbs or pellets, likely melted together in the heat of the explosion. that's the shrapnel the doctors have been digging out of victims in the hospitals. the second device appeared to be some kind of metal container. >> also new, in boston area hospitals some good news. 100 of the 183 people injured in monday's attack have been released. we're also learning more about who lost their lives. the third person killed, a chinese grad student studying at boston university. her name being withheld out of respect for her family's wishes. >> there is an ongoing investigation, a very active one. we are lucky that we have fran townsend with us, the national security analyst for cnn, former