Knowing now that Timothy was living in San Francisco in 1969 (in Haight-Ashbury area), I think it's probable that Jon probably knew very little. It was likely Timothy who knew everything, given that it was Timothy who stayed behind in Riverside until summer/fall 1966. It was Tim who knew Cheri. By then Jon was going to college in Stockton, CA, where he began in 1963.
It was Timothy who lived in San Francisco in the summer of 1969. Many mental health patients were released from the hospitals on or before June 30, 1969 due to that law going into effect on July 1. We know Ross was arrested in LA County some time in July 1969, according to Dave Peterson's notes. It is possible that Ross stayed with Tim after that, as he likely had no where else to live then while authorities were figuring out what to do with him. By then Jon lived in Minnesota and would not return to Berkeley until 1975 or 1976.
Remember that Katz said Ross lived in Santa Cruz and San Fran. This would explain why Timothy thought Ross was the killer and Jon doesn't.
Perhaps we should search for people who lived in the Haight in 1969 and ask if any of them might have known Ross. We got some hits when we searched Ross' Santa Cruz address, perhaps we should do similar searches for Tim's San Fran address or look at nearby spots that were popular in summer of 69.



