There is a picture of a piece of the pressure cooker.
Picture 3/6
The words “GAS ELECTRIC” on the outside circle
The words “NOX” on the inside circle
Picture 4/6
We can see the UL Listed mark.
We can see the pressure rating in part
“0.55/1.05 bar”
“?S 1.6 bar”
Picture 1/6
Being held by a hand.
The piece is approximately 4-5 hand widths (side facing about 3”) in diameter. So that makes it say 12-15” diameter pressure cooker.
With the actual parts in hand, they should have placed the specific make and model of the pressure cooker by now.
http://www.myfoxatlanta.com/story/21996004/exclusive-photos-boston-marathon-bomb