What is the test for establishing territorial jurisdiction in a murder case?

Defendant's contention assumes that territorial jurisdiction is a factual question for the jury. We need not decide that issue here. The trial court's duty to instruct on general principles of law and defenses not inconsistent with the defendant's theory of the case arises only when there is substantial evidence to support giving such an instruction. (People v. Montoya (1994) 7 Cal.4th 1027, 1047, 31 Cal.Rptr.2d 128, 874 P.2d 903.) Substantial evidence is evidence of reasonable, credible value. Here, defendant's theory that Nancy could have been killed in a state other than California is based on speculation, not substantial evidence.