Legal Question in DUI Law in California

1. Before trial.

2. With the clerk's office with service on the opposing party (in criminal cases, the district attorney's office).

There are some motions that cannot be filed except in front of the judge assigned to do the trial. Others can be run at any time before the trial and in front of any judge.

The answer depends on the type of motion.

If you're asking this to represent yourself, unfortunately, it demonstrates the need you have for an attorney. If representing yourself, you're going to be held to the rules of court, evidence, procedure, etc. You're going up against an attorney for the government who does know the rules and the law.

If you're asking for general knowledge, the more details would be required to answer your question.