individuals were involved. >> interesting. the lid of the pressure cooker. we're holding a pressure cooker here right now, chris cuomo, in his very hands. >> it's just to show what a common household item this is. juliette, you see something like this, like really, a bomb? because we don't really know. >> so, the common attribute of devices like this is not that they're hard or that a particular ideology is, you know, uses them. it is really that they're cheap. you get these at costco for pretty cheap. and so, that's really the only common attribute. >> take me through this type of pressure cooker bomb 101. what would you do with it? here it is. >> you put the detonation device inside. what we're starting to hear is that there might have been some trigger through in terms of detonating it. so the person might have dropped them one place, gone to another, and then exploded both devices. but we just don't know that for