California uses a combination of DMV and voter registration rolls to choose its jurors. They’ve been trying to broaden the jury pool for the last couple of years. Most courts have finally switched to one day jury duty, i.e. if you don’t get put on a case on the first day, you’re done for at least a year. Not all the courts in LA County have done this yet.
Los Angeles County asks for people to apply for grand jury duty. It uses 23 people and it’s a fulltime job. You get $25 a day for it plus mileage.