What is the test for admissible third-party evidence?

To be admissible, third-party evidence does not need to establish a "substantial proof of a probability" that someone other than the defendant committed the crime. (People v. Adams (2004) 115 Cal.App.4th 243, 252 (Adams).) Rather, the evidence need only be capable of raising a reasonable doubt about the defendant's guilt. (Ibid.) This does not mean, however, that any evidence, no matter how remote, must be admitted to show a third party's possible culpability. (Ibid.) " '[E]vidence 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.' [Citations.]" (Ibid.)