Gang Expert Testimony - Part I

I. California Street Terrorism Enforcement and Prevention (STEP) Act

A. Enactment of Act; Purpose

The California Street Terrorism Enforcement and Prevention (STEP) Act (Pen C §§186.20-186.33) was enacted in 1988 on a legislative finding that California was in a crisis caused by nearly 600 violent street gangs operating within the state. The legislature found that gang members threatened, terrorized, and committed a multitude of crimes against peaceful citizens, creating a clear and present danger to public order and safety. The legislature’s intent was to eradicate criminal activity by street gangs by focusing on patterns of criminal gang-related activity and on the on the organized nature of street gangs, which together, it deemed, were the chief sources of terror created by street gangs. Stats 1998, ch 1242.

B. Effect on Expert Testimony

Prior to People v McDaniels (1980) 107 CA3d 898, 902, 166 CR 12 (approving expert testimony regarding general social customs, mores, and practices of south central Los Angeles street gangs), and the enactment of the California Street Terrorism Enforcement and Prevention (STEP) Act (Pen C §§186.20-186.33) in 1988, the use of expert testimony in California regarding gangs was limited. Early cases involving the admissibility of gang-related evidence reflect a concern that, like traditional “bad character” evidence, such evidence would be improperly used to show a mere criminal disposition or “guilty by association.” Prior to the STEP Act, gang-related evidence, if permitted at all, was usually introduced to prove a non-character trait (such as motive, identity, or knowledge) or to impeach a witness through bias and motive to fabricate. See In Re Wing Y., 67 CA3d at 904 (evidence of common witness). But see Cardenas, 31 C3d at 904 (evidence of common gang membership to show bias was cumulative and, hence, prejudicial in light of other evidence showing possible bias).

With enactment of the STEP Act, the nature and prevalence of gang-related evidence changed dramatically. Expert opinion testimony regarding the culture, habits, and mores of street gangs became more commonplace as prosecutors were required to prove both the statutory definition of a “criminal street gang” and that the current offense was gang-related. See Pen C §186.22 (a)-(b), (d), (f); see also People v Hernandez (2004) 33 C4th 1040, 1044, 16 CR3d 880 (when criminal street gang allegation alleged, prosecution will often present evidence that would be inadmissible in a trial limited to charged offense); People v Gutierrez (2009) 45 C4th 789, 820, 89 CR3d 225. Since the passage of the STEP ACT, courts have permitted expert testimony in a wide range of areas, including:

The size, composition, or existence of gang
Gang turf or territory
An individual’s membership in, or association with, a street gang
The primary activities of a specific gang
Motivation for a particular crime (e.g. retaliation or intimidation)
Whether an offense was committed for the benefit of, at the direction of, or in association with a street gang
Rivalries between gangs (expert testimony concerning gang rivalry laid foundation for second degree murder conviction under natural and probable consequences doctrine)
Gang related tattoos, graffiti, hand signs and monikers

C. Penalty Provisions Under STEP Act

The California Street Terrorism Enforcement and Prevention (STEP) Act (Pen C §§186.20-186.22) makes the commission of crimnal offenses by individuals who are memebers of street gangs a seperate and distinctly punished offense, imposing certain penal consequences in the form of the following: