§6. Profile evidence offered against defendant
In certain situations, profile evidence can be admitted by expert testimony to establish some relevant issue other than guilt. Profile evidence identifies characteristics of certain crimes or criminals that, when taken together, establish a typical pattern of behavior. People v. Prince (2007) 40 Cal.4th 1179, 1226; People v. Jackson (2d Dist.2013) 221 Cal.App.4th 1222, 1237; see People v. Robbie (1st Dist.2001) 92 Cal.App.4th 1075, 1084. Such evidence is closely scrutinized, in large part because of the inference that it can create—that is, the defendant matches the profile presented and thus is guilty, even though some of the characteristics making up the profile are often as consistent with innocence as guilt. See Robbie, 92 Cal.App.4th at 1086-87 (profile evidence invites jury to improperly conclude that, because D manifested some characteristics, some of which can be as consistent with innocent behavior as illegal behavior, D committed charged offense). As a result, profile evidence is inadmissible if it attempts to link the defendant's characteristics to a profile to prove guilt. See, e.g., id. (while expert could have testified that rapists behave in different ways to rebut stereotype of all rapists being violent, she could not create rapist profile to perfectly match D's actions); People v. Walkey (4th Dist.1986) 177 Cal.App.3d 268, 278-79 (purpose of expert's testimony about profile of child abusers was to show that D fit within profile; expert did not explicitly link D to profile but his testimony, coupled with D's testimony about his own character and abuse, clearly implicated D). Profile evidence can be admissible, however, to establish some fact other than guilt or innocence. See, e.g., Jackson, 221 Cal.App.4th at 1238-39 (profile evidence about type of person who would commit crime was admissible in part to prove motive); People v. Derello (4th Dist.1989) 211 Cal.App.3d 414, 426 (profile evidence about drug-courier profile was admissible to prove knowledge and intent).
§6.1. Admitting profile evidence. To be admissible, profile evidence must be relevant, have an adequate foundation, and be more probative than prejudicial. See People v. Prince (2007) 40 Cal.4th 1179, 1226; People v. Smith (2005) 35 Cal.4th 334, 357, disapproved on other grounds, People v. Beck (2019) 8 Cal.5th 548.
1. Relevant. To be admissible, profile evidence must be relevant. See People v. Derello (4th Dist.1989) 211...
