I was browsing through Manson Direct (a Charles Manson cultist website) and this Manson painting from 2014 caught my eye:

(Edit: the photo was deleted. It was a painting by Manson featuring the Zodiac symbol/Celtic cross).

According to Howard Davis, Manson was aware of Howard’s Manson-Zodiac theory.(http://www.zodiackiller.com/mba/ozs/135.html)

Personally I do not buy Bruce Davis as a suspect, but I do wonder if Manson was making mischief with this painting. Or perhaps this verifies the influence of the Process Church, who also used the Celtic cross, on the Manson Family. (http://www.zodiackillersite.com/viewtopic.php?f=96&t=2202)