This case had a huge impact on me as a kid. I was in So. CA, but really had no concept at that time how far away we were from Northern CA. I can remember to this day, when they showed that sketch of him in his hood after Lake Berryessa attach and it scared the bejesus out of me.
At any rate, I don't believe he is alive. The officers that saw him after the Stine killing estimated his age as in his 40's. even if he was 10 years younger, he would be in his
70's.
I think he was likely a Dennis Rader type. Basically an average family guy that blended in. Probably a jerk, but functional enough, just like Rader. Also like Rader, he had a ned for his own brand of attention, thus the notes. My belief was always that, whoever he was, he would leave a note and probably some other proof of who he was when he died. However, I think it likely that his family, probably destroyed it.
I do not believe he was any of the named suspects.
Just my theory, of course, based on 40 + years of a morbid fascination with this case, born of youth and that creepy costume@!