Old murder case from San Diego 1981

[paris_paris]

I help people with their DNA results to find their birth families. I have been helping a woman (Marie) whose mother left New York and went to Mexico to give birth to her and gave her up for adoption, then returned to New York. Marie has DNA matches through 2 half siblings who are now deceased. A 3rd sibling left New York when she was young and went to California and the family lost track of her. We decided to try and find this 3rd sibling, and were alarmed with what we found.
This young woman went to California and got married and had a child. When she was 23, she and her husband argued and he shot her twice, killing her. I have found articles about his trial. He went to jail for 4 years. His sister took care of his son until he was released. In the last article there was a reference to a possible civil suit on behalf of “her daughter from a previous relationship”.
She had another child. The family is desperate to find her. The son is not responsive… it’s clearly a sensitive situation.
I am trying to figure out if there would be access to the case files. Maybe they mention the daughter’s name or who took her in?
This happened in San Diego in June 1981. If anyone has suggestions on where I could look next I would appreciate it.