RT Article T1 Gang activity and overall levels of crime: A new mapping tool for defining areas of gang activity using police record: Methodological Note JF Journal of quantitative criminology VO 16 IS 3 SP 369 OP 383 A1 Block, Richard 1944- LA English YR 2000 UL https://krimdok.uni-tuebingen.de/Record/1912563568 DO 10.1023/A:1007579007011