The conflict

Gang expert testimony was the factual backdrop for the Sanchez decision. The California Supreme Court held that a gang expert could not relate case-specific hearsay to the trier of fact unless a hearsay exception applied or competent evidence established the facts related. The Court explained that in the context of gang expert testimony, a particular defendant’s tattoos would be case-specific information, but the gang’s use of a particular tattoo as a symbol would not. General information about the gang and its history would be admissible background information, even if it was hearsay.

With that guidance, lower courts had little trouble agreeing that some gang information was case-specific, e.g., the defendant’s activities, associates, tattoos, and whether certain people had admitted gang membership. They also agreed that other information was background information, e.g., the gang’s history, symbols, primary activities, rivals, and territory.

The lower courts struggled, however, with so-called gang predicate crimes. Under California gang laws, the prosecution must establish that members of the gang have committed certain criminal offenses, or predicate crimes. Cal. Pen. Code, § 186.22(e)(1).

Some courts held that predicate crimes were background information because they were historical information independent of the people and events involved in the current case.1 Other courts reasoned that predicate crimes were case-specific because predicates were elements of the charged offense, requiring proof that particular people committed particular offenses.2 One court even held the commission of a predicate crime was background information, but the date it occurred was case-specific.3

It was a difficult question for everyone. The lower courts were almost evenly split, but the majority held that predicates were background.

The resolution

The Supreme Court resolved the conflict in 2021, siding with the (slight) minority view. People v. Valencia (2021) 11 Cal.5th 818.

The Valencia Court acknowledged that evidence of predicate crimes did not “fall neatly into the description Sanchez provided.” Valencia, supra, 11 Cal.5th, at p. 839. Some predicate offenses occur before the case being tried and are committed by people who are not on trial. Ibid. But the Court reasoned in this context that proof of predicate crimes requires evidence of particular offenses on specific occasions.

[Background] information stands in contrast to information regarding the commission of a particular offense on a specific occasion. Experts with no personal knowledge of case-specific facts, or who do not rely on other admissible evidence establishing those facts, are simply “regurgitat[ing] information from another source.” (Veamatahau, supra, 9 Cal.5th at p. 34, 259 Cal.Rptr.3d 205, 459 P.3d 10.) This is the practice rejected in Veamatahau and warned against in Sanchez. “What an expert cannot do is relate as true case-specific facts asserted in hearsay statements, unless they are independently proven by competent evidence or are covered by a hearsay exception.” (Sanchez, supra, 63 Cal.4th at p. 686, 204 Cal.Rptr.3d 102, 374 P.3d 320; see Veamatahau, at pp. 33–34, 259 Cal.Rptr.3d 205, 459 P.3d 10.) Without independent admissible evidence of the particulars of the predicate offenses, the expert’s hearsay testimony cannot be used to supply them. In the absence of any additional foundation, the facts of an individual case are not the kind of general information on which experts can be said to agree. Valencia, supra, at p. 838.

My mental model

I think my approach to Veamatahau stands up:

[I]f I change the players or the events in this case, does that change the hearsay information?

The Valencia court put it similarly:

Hallmarks of background facts are that they are generally accepted by experts in their field of expertise, and that they will usually be applicable to all similar cases. Valencia, supra, 11 Cal.5th 818, 836.

In our analysis, we must remember that what I call “players” and Sanchez calls “participants” is a more expansive definition than the parties. It depends on the factual and legal context of the case. There are causes of action, other than criminal gang cases, that involve players and events beyond the instant parties:

  • Cases where knowledge is an element of the cause of action
  • Harassment or stalking actions that require proof of patterns of conduct

Concentrate on the relationship between the hearsay evidence and the participants and events in the case. The closer the relationship, the more likely the information is case-specific.

The future of civil cases?

In his guide to California Expert Witnesses San Francisco Judge Curtis E. A. Karnow demonstrates how the case-specific/background distinction can become difficult in civil cases: if an expert testifies that a certain truck has bad brakes, that experts in the field know this, and that the defect is true regardless of the plaintiff’s experience in the case at bar, is that case-specific?4

Sometimes, the gap between case-specific and background hearsay can be like a hairline crack in a mobile phone screen: you have to tilt it just right to see it clearly. Perhaps future cases will give us a more discriminating method.

  1. See, e.g., People v. Bermudez, 45 Cal.App.5th 358; People v. Blessett, 22 Cal.App.5th 903; People v. Vega-Robles, 9 Cal.App.5th 382; People v. Meraz, 6 Cal.App.5th 1162; People v. Meraz, 30 Cal.App.5th 768. ↩︎

  2. See, e.g., People v. Ochoa, 7 Cal.App.5th 575, 212 Cal.Rptr.3d 703; People v. Thompkins, 50 Cal.App.5th 365; People v. Lara, 9 Cal.App.5th 296. ↩︎

  3. People v. Garcia, 46 Cal.App.5th 123 (6th Dist. 2020), review denied, (May 27, 2020) and review denied, (June 10, 2020). ↩︎

  4. Karnow, California Expert Witnesses (bepress 2020), at p. 30. ↩︎