I came across this poster while sorting some old files. Sam Gross (now at Michigan Law and editor of the National Registry of Exonerations) and I worked on this case in the summer of 1972, after our 2L year at Boalt Hall.
The Wikipedia page for the case is here.
Did you work on behalf of specific defendants or attorneys? One of my favorite books by a Leftist defense attorney from that period is Charles Garry's* (with Art Goldberg) Streetfighter in the Courtroom: The People's Advocate (E.P. Dutton, 1977). As you no doubt know, Garry worked on behalf of Johnny Spain (although as I understand it, the group agreed to fight the case together), a Black Panther and the youngest defendant (Garry said Spain's story was 'the story of American racism'), who was paroled in 1988.
* b. Garabed Hagop Robutlay Garabedian