Seeking LA Superior Court court transcript in 1970s

Hello, I'm seeking a court transcript from 1973 from the LA Superior Court. We sent through a request years ago but never had a response either way, so we're currently trying again. However, I know California doesn't keep all of its records, especially after so many years. My research does show that they do a rotating archive and also keep things of interest, and it was a murder trial that had some local reporting, so might quality. But if it was going to be kept in an archive, where else would be good to look?

Relevant information - Case name is probably called something like Baxter v. Baxter. It was the murder trial of Jack Lawrence Baxter by Barbara Anne Baxter (these were my grandparents). The Case number:is A012975 and the murder date was October 21, 1972. The conviction date was April 6, 1973. She was found sane in the slaying and guilty but sentenced to a maximum security mental institution. The Judge was Ernest Kelley, the Deputy District Attorney was Dinko Bozanich, and co-counsel was Robert Morrel.

If they're out there, I'd really like to find them. I'm writing a book about what happened, but my mom was only called in to testify against her mother briefly twice, and she was understandably distressed both times and doesn't remember that much. There are a few details in newspaper articles released around that time, but so much is relatively unknown to me. Thank you for any help you can provide.