Third-party Culpability Evidence (California)
All evidence having any tendency in reason to prove or disprove a disputed fact is admissible. (Evid. Code, 210.) "In general, third party culpability evidence is admissible if it 'raises a reasonable doubt of defendant's guilt.' This does not mean, however, that no reasonable limits apply. Evidence that another person had 'motive or opportunity' to commit the charged crime, or had some 'remote' connection to the victim or crime scene, is not sufficient to raise the requisite reasonable doubt. . . . Third party culpability evidence is relevant and admissible only if it succeeds in 'linking the third person to the actual perpetration of the crime.' " (People v. DePriest (2007) 42 Cal.4th 1, 43.)
"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." (People v. Hall (1986) 41 Cal.3d 826, 833.)
In Holmes v. South Carolina (2006) 547 U.S. 319, the court held that an evidentiary rule that a defendant could not introduce third party culpability evidence if the prosecution introduced forensic evidence that strongly supported a guilty verdict violated the defendant's federal constitutional rights to a fair trial and to present a defense. (Id. at pp. 330-331.)
The Holmes court concluded that "by evaluating the strength of only one party's evidence, no logical conclusion can be reached regarding the strength of contrary evidence offered by the other side to rebut or cast doubt." (Id. at p. 331.)
In People v. Samaniego (2009) 172 Cal.App.4th 1148, the court rejected that the reasoning in Holmes v. South Carolina (2006) 547 U.S. 319 applied in a case where the defendant sought to introduce evidence that a third party committed the murder for which the defendant was accused.
"We do not find Holmes controlling here. It dealt with a judicially created rule precluding third party culpability evidence if the prosecution presented strong evidence, especially forensic evidence. It thereby focused the inquiry on the strength of the prosecution's case, not the probative value or potential adverse effects of the third party culpability evidence. Holmes did not consider the extent to which a trial court might consider the strength of the prosecution's evidence in exercising its discretion to determine whether the third party evidence could raise a reasonable doubt as to the defendant's guilt. In the matter before us, the trial court's focus was on the lack of connection between the third party and the crime, not on the strength of the People's case. Holmes is also distinguishable on its facts, as the third party in that case was strongly linked to the crime by having told numerous people that the charged defendant was innocent and that the third party himself committed the crime. No such compelling evidence is present here." (Id. at p. 1176.)