Both articles are from the Hayward Daily Review, Hayward CA. The first is dated Nov. 1, 1975 and the second dated March 23, 1976.
The last name is unusual so I think this is the correct one, I didn’t find any other David Seligman that was murdered. No mention of any writing/graffiti and someone else was convicted of the murder of this poor child.
I looked at Ancestry and did find a death record for a David Seligman who had lived on Natomas in San Francisco but I was not able to find any newspaper articles on him. He was relatively young when he died so perhaps it was murder. At least now there is a date to work with to try to figure it out.
Daniel the next time I go to the Santa Rosa library I will see if I can find an article in the Chronicle microfilms. Having a date for when the older David Seligman died helps. Not sure when I will do that though.