What is the test for third party culpability in a murder case?

In People v. Hall (1986) 41 Cal.3d 826, 226 Cal.Rptr. 112, 718 P.2d 99, this court articulated the standard California courts apply in determining the admissibility of third party culpability evidence. We said: To be admissible, the third-party evidence need not show substantial proof of a probability that the third person committed the act; it need only be capable of raising a reasonable doubt of defendant's guilt. At the same time, we do not require that any evidence, however remote, must be admitted to show a third party's possible culpability. As this court observed in [ People v.] Mendez [ (1924) 193 Cal. 39, 51, 223 P. 65], evidence of mere motive or opportunity to commit the crime in another person, without more, will not suffice to raise a reasonable doubt about a defendant's guilt: there must be direct or circumstantial evidence linking the third person to the actual perpetration of the crime. ( Id. at p. 833, 226 Cal.Rptr. 112, 718 P.2d 99.)