Chapter 4 - §7. Syndrome evidence offered to explain behavior

• Jurisdiction: United States

§7. Syndrome evidence offered to explain behavior

In certain situations, syndrome evidence can be admitted by expert testimony to explain behaviors common to a certain class of victims; it generally cannot be admitted to establish that a defendant committed a crime. See, e.g., People v. Bledsoe (1984) 36 Cal.3d 236, 247-48 (while syndrome evidence can be admitted to rebut misconceptions about how victims react to certain situations, it was not admissible to prove that rape occurred). Syndrome evidence identifies particular behavior traits or typical conduct of people who have been victimized by specific kinds of criminal conduct. See People v. Humphrey (1996) 13 Cal.4th 1073, 1088; People v. McAlpin (1991) 53 Cal.3d 1289, 1300-01; see, e.g., Jennifer K. v. Shane K. (1st Dist.2020) 47 Cal.App.5th 558, 585 (rape-trauma syndrome evidence is admissible to rebut inference that alleged rape did not occur due to portrayal of victim's conduct as inconsistent with having been raped). California has statutorily provided for the introduction of intimate-partner-battering syndrome (otherwise known as intimate-partner-violence syndrome) and human-trafficking syndrome although evidence can be presented on a variety of other syndromes including rape-trauma and child-sexual-abuse-accommodation syndromes. See Evid. C. §§1107, 1107.5; People v. Brown (2004) 33 Cal.4th 892, 905-06; People v. Sanchez (4th Dist.1989) 208 Cal.App.3d 721, 735. Syndrome evidence can be introduced by the prosecution or the defendant. See Evid. C. §1107(a); Humphrey, 13 Cal.4th at 1087-88; Sanchez, 208 Cal.App.3d at 735. If the prosecution presents syndrome evidence, it can do so during its case-in-chief as long as the defendant has already challenged the credibility of the person suffering from the syndrome. See, e.g., People v. Housley (1st Dist.1992) 6 Cal.App.4th 947, 956 (prosecution could introduce syndrome evidence during case-in-chief when D placed complaining witness's credibility at issue; witness's credibility was at issue when witness recanted and testified contrary to her pretrial statements).

§7.1. Admitting syndrome evidence. To be admissible, syndrome evidence must be relevant, have an adequate foundation, and be more probative than prejudicial.

1. Relevant.

(1) Generally. To be admissible, syndrome evidence must be relevant. See "When is evidence relevant," ch. 1, §2. Syndrome evidence is generally considered relevant if it is admitted to explain a myth or misconception about how...