Ed Huntress fired this volley in
:

Lloyd, don't you think they know by now exactly what powder(s) was
used? BP leaves so much residue that no one who's used it could miss
it. And the others must leave enough chemical residue to clearly
identify them, right?

I assume so, although chemistry is something about which I know next
to nothing. My guess is that we'll hear pretty soon what they came up
with in the lab -- if it hasn't come out already, and I just missed
it.


Oh, I'm certain that they are absolutely sure of what was used -- they
just haven't published it -- for two reasons.

1) they want to preserve evidence information for a prosecution. Giving
away the info to the public might somehow contaminate any testimony that
comes from the perp.
2) they want to further restrict our access to explosive substances, in
general. I'm licensed with ATF, and wouldn't have any issues, other than
perhaps some more minor paperwork. But the average person - say a BP
shooter, or an amateur pyrotechnician - would have a lot of their
freedoms restricted. That's what they want.

Lloyd