Technically, neither stars nor angels belong to any particular religion. But to the mind of Mr. Sutley, 65, a veteran who has fought to keep religion out of public meetings and buildings, the symbolism was clear.

Image Sonoma County in California banned symbols like angels and stars from its buildings. Credit... Jeff Kan Lee/Press Democrat

“For most people, a star atop a tree at this time of season represents the star of Bethlehem, which is a cult symbol, the cult being Christianity,” he said, adding that the government should be neutral on religion.

Sonoma County officials conferred with their lawyers, and on Monday the acting county administrator, Chris Thomas, asked county departments to remove stars, angels or any other religious symbols “so that we can celebrate the season yet not appear to endorse Christian or other religious doctrines.”

Mr. Thomas cited a 1989 Supreme Court decision, Allegheny v. A.C.L.U., which stated that while Christmas trees could be seen as secular, they could also be seen as religious if decorated with religious symbols.

All of which pleased Mr. Sutley, who said he had found about a half-dozen stars on other trees around the building in Santa Rosa. He said he found none in the social services department, in which he found a religious placard during the holidays last year. (It, too, was removed.)