Courts regularly qualify police officers as "gang experts" in prosecutions under California's Street Terrorism Enforcement and Prevention Act. This note argues that absent independent, scientifically-verifiable expertise, the use of police officers as gang experts violates even California courts' low standard for admitting expert evidence. The note begins by analyzing the language and the legislative intent of the Act, including its substantive offense components, sentence enhancement and alternative penalty sections. The note next discusses the evidentiary power of police officers when testifying as gang experts, focusing on the substantial risk of prejudice resulting from such testimony and the officers' ability to convert otherwise weak cases into convictions on both underlying offenses and gang-crime enhancements. The authors then argue that in California admission of the testimony of these "gang experts" should be governed by the Kelly/Frye standard for the admission of novel sociological testimony. Finally, the authors propose techniques to help defense attorneys mitigate the prejudicial effect of police officer/gang expert testimony until an appropriate standard is adopted.
Christopher McGinnis and Sarah Eisenhart,
Interrogation is Not Ethnography: The Irrational Admission of Gang Cops as Experts in the Field of Sociology,
7 Hastings Race & Poverty L. J. 111
Available at: https://repository.uchastings.edu/hastings_race_poverty_law_journal/vol7/iss1/4