Never ever heard of this that the atty Vasilios Basil Choulos (1927-2003) communicated with Zodiac:

California City Directories
San Francisco 1970 C:

Choulos Vasilios B
Belli Ashe Ellison Choulos & Lieff attys
722 Montgomery
981-1849

https://www.sfgate.com/bayarea/article/ … 627184.php

Vasilios Basil Choulos — colorful S.F. lawyer
By Peter Fimrite Published 4:00 am PST, Friday, March 21, 2003

Quote:
Known to most people as "Bill," he was Melvin Belli’s law partner for 18 years until their famously acrimonious split in 1980. They practiced law together at a historic old brick building in North Beach that was decorated like a 19th century brothel, replete with ornate doorways and brass knobs.

Quote:
Mr. Choulos communicated with the infamous Zodiac killer and attempted to set up a meeting, but the killer apparently stood him up. His client list during the 1960s was a counterculture kaleidoscope, including Abby Hoffman, Jerry Rubin, Lenny Bruce and Timothy Leary.
His greatest passion, however, was protecting the disadvantaged from persecution and corporate irresponsibility.