Legal Question in Criminal Law in California

Any 4 year degree will do.

It doesn't matter. Law schools don't care what their applicants major in as long as they learn how to think critically, write well and analyze problems logically. Nearly every undergraduate program will give students the opportunity to learn these skills. There are a few majors -- like some programs in music performance and studio art -- that don't directly involve these skills, but students in those fields can take electives in other departments in order to develop the necessary skills and knowledge.

For what it's worth, I majored in computer science.

Any approved bachelor's degree will do. If you are serious about criminal defense work, you may want a few science electives to keep up with forensics. A well rounded education is best.