This study examines the trends in and spatial distribution of recorded offending by Australian outlaw motorcycle gang (OMCG) affiliates at the onset of a territorial conflict between two clubs in the state of New South Wales.
Results show an increase in recorded offending by OMCG affiliates involved in the conflict and based in the disputed territory. Comparable increases in recorded offending by these clubs were not detected in the areas surrounding this territory or in the rest of New South Wales, and there was little mobility into the conflict region by those outside of it. There was a smaller, short-lived increase in recorded crime by affiliates of other gangs in the conflict region but not elsewhere. In short, changes in offending patterns were largely limited to the clubs involved in the conflict and localised to the territory in dispute.
This research can help guide focused law enforcement responses during periods of gang conflict.
URLs correct as at December 2022
Amer AA 2020. On k-means clustering-based approach for DDBSs design. Journal of Big Data 7(31): 1–31. https://doi.org/10.1186/s40537-020-00306-9
Anitha P & Patil MM 2019. RFM model for customer purchase behavior using k-means algorithm. Journal of King Saud University – Computer and Information Sciences. Advance online publication. https://doi.org/10.1016/j.jksuci.2019.12.011
Australian Criminal Intelligence Commission 2021. Gangs. https://www.acic.gov.au/about/priority-crime-themes/gangs
Batool F & Hennig C 2021. Clustering with the average silhouette width. Computational Statistics & Data Analysis 158: 107190. https://doi.org/10.1016/j.csda.2021.107190
Bora DJ & Gupta AK 2014. Effect of different distance measures on the performance of k-means algorithm: An experimental study in Matlab. International Journal of Computer Science and Information Technologies 5(2): 2501–2506.
Brantingham PJ, Tita GE, Short MB & Reid SE 2012. The ecology of gang territorial boundaries. Criminology 50(3): 851–885. https://doi.org/10.1111/j.1745-9125.2012.00281.x
Brantingham PJ, Yuan B & Herz D 2021. Is gang violent crime more contagious than non-gang violent crime? Journal of Quantitative Criminology 37: 953–977. https://doi.org/10.1007/s10940-020-09479-1
Chopde NR & Nichat MK 2013. Landmark based shortest path detection by using A and haversine formula. International Journal of Innovative Research in Computer and Communication Engineering 1(2): 298–302.
Decker SH, Melde C & Pyrooz DC 2013. What do we know about gangs and gang members and where do we go from here? Justice Quarterly 30(3): 369–402. https://doi.org/10.1080/07418825.2012.732101
Dowling C, Boland D, Morgan A, Webster J, Chiu Y & Lowe R 2021. The changing culture of outlaw motorcycle gangs in Australia. Trends & issues in crime and criminal justice no. 615. Canberra: Australian Institute of Criminology. https://doi.org/10.52922/ti78054
Dowling C & Morgan A 2021. Criminal mobility of outlaw motorcycle gangs in Australia. Trends & issues in crime and criminal justice no. 619. Canberra: Australian Institute of Criminology. https://doi.org/10.52922/ti04992
Franses PH 2016. A note on the mean absolute scaled error. International Journal of Forecasting 32(1): 20–22. https://doi.org/10.1016/j.ijforecast.2015.03.008
Gorrey M & Inman M 2018. The great bikie club schism that sparked the battle for Canberra’s south side. Canberra Times. https://www.canberratimes.com.au/story/6030289/the-great-bikie-club-schism-that-sparked-the-battle-for-canberras-south-side/
Hyndman RJ & Khandakar Y 2008. Automatic time series forecasting: The forecast package for R. Journal of Statistical Software 27(3): 1–22. https://doi.org/10.18637/jss.v027.i03
Hyndman RJ & Koehler AB 2006. Another look at measures of forecast accuracy. International Journal of Forecasting 22(4): 679–688. https://doi.org/10.1016/j.ijforecast.2006.03.001
Jain A & Dubes R 1988. Algorithms for clustering data. Englewood Cliffs: Prentice Hall
Knowles G 2018. Rock Machine regain foothold in Perth after bikie ‘war’. West Australian, 24 January. https://thewest.com.au/news/crime/rock-machine-regain-foothold-in-perth-after-bikie-war-ng-b88719123z
Lakeman L, Benier K & Wickes R 2021. Outlaw motorcycle gangs and neighbourhood crime. Current Issues in Crime and Criminal Justice 33(4): 466–482. https://doi.org/10.1080/10345329.2021.1922157
Lauchs M 2020. A global survey of outlaw motorcycle gang formation. Deviant Behaviour 41(12): 1524–1539. https://doi.org/10.1080/01639625.2019.1630217
Lauchs M, Bain A & Bell P 2015. Outlaw motorcycle gangs: A theoretical perspective. London: Palgrave Macmillan. https://doi.org/10.1057/9781137456298
Lauchs M & Gilbert J 2017. Outlaw motorcycle gangs. In R Sarre & A Deckert (eds), The Palgrave handbook of Australian and New Zealand criminology, crime and justice. Switzerland: Springer: 159–174. https://doi.org/10.1007/978-3-319-55747-2_11
Lengyel A & Botta-Dukát Z 2019. Silhouette width using generalized mean: A flexible method for assessing clustering efficiency. Ecology and Evolution 9(23): 13231–13243. https://doi.org/10.1002/ece3.5774
Lleti R, Ortiz MC, Sarabia LA & Sanchez MS 2004. Selecting variables for k-means cluster analysis by using a genetic algorithm that optimizes the silhouettes. Analytica Chimica Acta 515(1): 87–100. https://doi.org/10.1016/j.aca.2003.12.020
McGloin JM & Collins ME 2015. Micro-level processes of the gang. In SH Decker & CD Pyrooz (eds), The handbook of gangs. Chichester: John Wiley & Sons: 276–293. https://doi.org/10.1002/9781118726822.ch15
McNab D 2013. Outlaw bikers in Australia: The real story. Sydney: Pan Macmillan
Monterosso S 2018. From bikers to savvy criminals. Outlaw motorcycle gangs in Australia: Implications for legislators and law enforcement. Crime, Law and Social Change 69: 681–701. https://doi.org/10.1007/s10611-018-9771-1
Morgan A, Dowling C & Voce I 2020. Australian outlaw motorcycle gang involvement in violent and organised crime. Trends & issues in crime and criminal justice no. 586. Canberra: Australian Institute of Criminology. https://doi.org/10.52922/ti04282
Quinn JF & Forsyth CJ 2011. The tools, tactics, and mentality of outlaw biker wars. American Journal of Criminal Justice 36: 216–230. https://doi.org/10.1007/s12103-011-9107-5
Quinn JF & Forsyth CJ 2009. Leathers and rolexs: The symbolism and values of the motorcycle club. Deviant Behavior 30(3): 235–265. https://doi.org/10.1080/01639620802168700
Raykov YP, Boukouvalas A, Baig F & Little MA 2016. What to do when k-means clustering fails: A simple yet principled alternative algorithm. PLoS ONE 11(9): e0162259. https://doi.org/10.1371/journal.pone.0162259
Sanderson K, Bell P & Merrington S 2014. A case study analysis of the Montreal (Canada) chapter of the hells Angels outlaw motorcycle club (HAMC) (1995–2010): Applying the crime business analysis matrix (CBAM). Mustang Journal of Law and Legal Studies 7: 18–38
Tita GE & Radil SM 2011. Spatializing the social networks of gangs to explore patterns of violence. Journal of Quantitative Criminology 27: 521–545. https://doi.org/10.1007/s10940-011-9136-8
Valasik M & Tita GE 2018. Gangs and space. In GJN Bruinsma & SD Johnson (eds), The Oxford handbook of environmental criminology. New York: Oxford University Press: 839–867. https://doi.org/10.1093/oxfordhb/9780190279707.013.25
Veno A 2012. The brotherhoods: Inside the Australian motorcycle clubs. Sydney: Allen & Unwin
von Lampe K & Blokland A 2020. Outlaw motorcycle clubs and organized crime. Crime and Justice 49: 521–578. https://doi.org/10.1086/708926