The reason to dispose of the jar of vaseline is because the vaseline was a component in the making of the bombs.
Vaseline is flammable and nicely non-liquid, ie, you could put it into a container that has some small holes in it and it won’t all run out like a liquid would. All you need to do is mix in enough oxidizer, get an initiator into contact with the mixture and you’re good to go.
Some heavy-duty oxidizer like potassium perchlorate would probably make a reasonable low-yield explosive like what we saw in the films out of Boston.
Where do you find potassium perchlorate?
Some types of colored fireworks, that’s where. Jeez, doesn’t anyone here study science any more? This is high-school level chemistry, folks.
The fact that the friends scooped up the computer, the vaseline and the empty fireworks containers means that the friends had prior knowledge. I’ll wager that the DA will be charging at least one of the three stooges with conspiracy.
Re: the lockdown. The geography of that area is that the college campus near the base of Cape Cod is about 1 hour south of Boston. The lockdown encompassed Boston and its immediate suburbs. I’m pretty sure where the college campus was wasn’t under lockdown.