I don’t know if this has been mentioned before but what if the Zodiac didn’t have a connection with Humble Oil directly as in an employee of theirs but had dealings with them as an employee of another who had Humble Oil as a client? I’m thinking the California Department of Weights and Measures. They inspect anything that requires, obviously, weights, measure and labeling. Hospitals, petroleum industry and prisons are inspected iin California. Also thinking about the gas stations they inspect and Phillips 66 pickup of a map. In addition to that, this department, is part of the Department of Agriculture which is also something we see in relation to the Zodiac.

Soze