Sounds like the work of a homegrown idiot. In junior high school.
“Happy New Year. We did it.”
Sounds like the homegrown idiot congratulating Congress on loosening up security measures.
Since the letters were mailed so far in advance, it seems to me there’s a bit more planning involved than a simple junior high schooler would be capable.
IMO, the investigation should be focusing on that fact; it should help narrow the list of suspects. I didn’t know that mail would take that long to get to the congressional offices. Is that common knowledge? Am I just slow in that regard? I can’t see your usual peacenick hippie type knowing that, or planning that carefully.