CNN Anderson Cooper 360 May 2, 2013 00:09:00
A insulator between metal and in this case, perhaps, the inside powder found in a fire work. so that's very specific to bomb-making. and anderson, i think that's telling in two different ways. number one, it tells you that dzhokhar, not just his older dead brother, but dzhokhar, had some kind of proficiency in at least knowing how to put together bombs. and number two, it let's you know that at least one of these students arrested today knew that. because let's face it. you get rid of the computer, you get rid of a backpack with empty fireworks inside. why would you then go and reach for a jar...
Source: archive.org