How can I file for and serve a subpoena to someone that I need to testify on my behalf?

A non-party witness cannot generally be compelled by a subpoena issued by appear for a court hearing in California.

However, you may be able to take the deposition an of an out-of-state resident at his or her place of residence.

The right to take such a deposition would depend on the law of the state where the individual resides.

If you were able to take the deposition of an out-of-state resident, you could then use that deposition in lieu of live testimony at a hearing or trial in California.

Of course, you could always ask the witness to appear at a hearing in California voluntarily if you paid his or her travel expenses.

You really need the advise of a skilled litigator to handle this matter.

PLEASE NOTE THAT THIS RESPONSE SHOULD NOT BE CONSTRUED AS A LEGAL OPINION OR ADVISE, AND DOES NOT CREATE AN ATTORNEY-CLIENT RELATIONSHIP. IN ORDER TO RENDER A LEGAL OPINION OR ADVISE, THE RESPONDING ATTORNEY WOULD NEED FAR MORE INFORMATION THAN HAS BEEN PROVIDED, AND WOULD NEED TO BE RETAINED PURSUANT TO A WRITTEN FEE AGREEMENT.