On October 8, 1970, the Marin County Courthouse was bombed. A group known as the Weathermen later claimed responsibility for the action.
Please note that this incident happened right 3 days after Z had sent a postcard as well as 4 days before Z had – again – sent a letter.
QT
http://en.wikipedia.org/wiki/Weatherman_(organization )
http://en.wikipedia.org/wiki/Marin_Coun … e_incident
*ZODIACHRONOLOGY*
Which letter four days after are you referring to, Quicktrader? I’m guessing you’re referring to the 10/5/70 "13-hole card" and some unconfirmed letter. It would be an interesting observation because it does seem Z paid attention to the activities of groups like the Weather Underground and Black Panthers, commenting on the Park Station bombing and possibly the SLA and killing of Officer Radetich.
Z. paid attention to everything in the news, and probably reacted to stories which bumped him down the order of news coverage. I suspect HIS bomb threat was prompted by the attacks in New York going on at the time. (Pet theory.)