Gang Expert Testimony - Part III

Posted by Chris Morales on Mon, Nov 04, 2013 @ 11:46 AM

II. Expert Testimony on Step Act Provisions

A. Use of Expert Opinion Testimony

The use of experts to testify in court on the subject of gangs in criminal cases is increasingly common. Expert gang testimony generally falls into two categories:

  • Testimony involving statutory gang allegations under Pen C §186.22 and
  • Testimony involving some other material issue in dispute such as motive, identity, knowledge, or bias.

Whether offered to prove up a statutory gang element or a disputed issue, expert opinion testimony regarding gangs typically revolves around the general custom, culture, and habits of the gang in question.

Note: The term gang is used in this chapter in the vernacular sense unless otherwise specified, and it should not be confused with the statutory term “criminal street gang” as defined by the STEP Act. See Pen C §186.22(f).

“The use of expert testimony in the area of gang sociology and psychology is well established.” People v Olguin (1994) 31 CA4th 1355, 1370, 37 CR2d 596. For instance, one appellate court found that a deputy sheriff was qualified as an expert to render opinions “at some length regarding the general social customs, mores and practices of south central Los Angeles street gangs.” People v McDaniels (1980) 107 CA3d 898, 902, 166 CR12. The deputy sheriff testified that (1) “a person who lives in the territory of a particular gang is automatically associated with that gang by members” of rival gangs; (2) fist fights between two rival gang members usually take place at “mutual” sites; (3) if a gang traveled to a rival gang’s territory, one would expect more than just a fist fight; and (4) it would be unusual for various Crip fractions (an African American-gang founded in Los Angeles) to band together when taking retaliatory action. 107 CA3d 902.

Note: The California Supreme Court has held that “the subject matter of the culture and habits of criminal street gangs” is of “particular relevance: where a gang enhancement is alleged. People v Gardeley (1996) 14 C4th 605, 617, 59 CR2d 356.

B. Areas of Expert Testimony

While the substantive offense, sentence enhancement, and alternate penalty provisions obviously differ in application and, to some extent, criteria, they each require proof of the existence of the statutorily defined “criminal street gang” and that the current offense was gang-related. See §§17.3-17.6. The substantive offense provision requires that a person actively participates in a criminal street gang with knowledge that members are engaging in, or have engaged in, a pattern of criminal gang activity, and who willfully promotes, furthers, or assists in any felonious criminal conduct by members of the gang. Pen C §186.22(a); see §17.4. The enhancement and alternate penalty provisions, for instance, require that an offense was “committed for the benefit of, at the direction of, or in association with any criminal street gang, with the specific intent to promote, further, or assist in any criminal conduct by gang members.” Pen C §186.22(b), (d); see §§17.5-17.6.

1. Expert Opinion on “Criminal Street Gang”

A “criminal street gang” is defined as any “ongoing organization, association, or group of three or more persons, whether formal or informal, having as one of its primary activities the commission of one or more of the criminal acts” enumerated in Pen C §186.22(e)(1)-(25) or §186.22(e)(31)-(33), having a “common name or common identifying sign or symbol, and whose members individually or collectively engage in or have engaged in a pattern of criminal gang activity.” Pen C §186.22(f). Case law has evolve and refined this definition into four criteria (People v Gardeley (1996) 14 C4th 605, 620, 59 CR2s 356):

  • Primary activities include commission of enumerated criminal acts;
  • Members engage in a pattern of criminal gang activity;
  • Organization, association, or group includes three or more persons, whether formal or informal; and
  • Organization, association, or group has a common name or common identifying sign or symbol

The two criteria that involve the greatest amount of litigation are the “primary activities” and “pattern of criminal gang activity” elements. These are the criteria most susceptible to challenge because they break down into further legal components. Close attention should be paid to the establishment of either of those criteria.

The Morales Law Firm would like to Thank

Scientific Evidence in California Criminal Cases for sharing this information with us.


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Tags: terrorized, threatened, crimes, gang, gang-related activity