• McLean, R. & Densley, J. (2020). Scotland’s gang members: life and crime in Glasgow. Palgrave Macmillan.
  • McLean, R. Robinson, G. & Densley, J. (2020). County lines: criminal networks and evolving drug markets in Britain. Springer.
  • Bumgarner, J., Hilal, S., & Densley, J. (2016). Minnesota’s criminal justice system. Carolina Academic Press.
  • Densley, J. (2013). How gangs work: An ethnography of youth violence. Palgrave Macmillan.

Edited Volumes

Densley, J., Deuchar, R. & Harding, S. (2020). Special issue: street gangs, group offending and violence. Youth Justice, 20(1–2), 1–180.

Peer-Reviewed Articles

42. Rahman, M., McLean, R., Deuchar, R. & Densley, J. (in press). Who are the enforcers? The motives and methods of muscle for hire in West Scotland and the West Midlands. Trends in Organized Crime. doi: 10.1007/s12117-020-09382-y.

41. Peterson, J., Densley, J. & Erickson, G. (in press). Evaluation of 'the R-Model' crisis intervention de-escalation training for law enforcement. The Police Journal. doi: 10.1177/0032258X19864997.

40. Whittaker, A., Densley, J. & Moser, K. (2020). No two gangs are alike: the digital divide in street gangs’ differential adaptations to social media. Computers in Human Behavior, 110, 106403. doi: 10.1016/j.chb.2020.106403.

39. Deuchar, R., Harding, S. McLean, R. & Densley, J. (2020). Deficit or credit? A comparative, qualitative study of gender agency and female gang membership in Los Angeles and Glasgow. Crime & Delinquency, 66(8), 1087–1114. doi: 10.1177/0011128718794192.

38. Densley, J. & Pyrooz, D. (2020). The Matrix in context: taking stock of police gang databases in London and beyond. Youth Justice, 20(1–2), 11–30. doi: 10.1177/1473225419883706.

37. Densley. J., Deuchar, R. & Harding, S. (2020). An introduction to gangs and serious youth violence in the United Kingdom. Youth Justice, 20(1–2), 3–10. doi: 10.1177/1473225420902848.

36. Roks, R. & Densley, J. (2020). From brakers to bikers: the evolution of the Dutch Crips ‘gang’. Deviant Behavior, 41(4), 525–542. doi: 10.1080/01639625.2019.1572301.

35. Whittaker, A., Densley, J., Cheston, L., Tyrell, T., Higgins, M., Felix-Baptiste, C. & Havard, T. (2020). Reluctant Gangsters revisited: the evolution of gangs from postcodes to profits. European Journal on Criminal Policy and Research, 26(1), 1–22. doi: 10.1007/s10610-019-09408-4.

34. Deuchar, R., Miller, J. & Densley, J. (2019). The lived experience of stop and search in Scotland: there are two sides to every story. Police Quarterly, 22(4), 416–451. doi: 10.1177/1098611119849646.

33. Harding, S. Deuchar, R., Densley, J., & McLean, R. (2019). A typology of street robbery and gang organization: insights from qualitative research in Scotland. The British Journal of Criminology, 59(4), 879–897. doi: 10.1093/bjc/azy064.

32. Densley, J., McLean, R., Deuchar, R. & Harding, S. (2019). Progression from cafeteria to à la carte offending: Scottish organised crime narratives. The Howard Journal of Crime and Justice, 58(2), 161–179. doi: 10.1111/hojo.12304.

31. Densley, J. & Pyrooz, D. (2019). A signaling perspective on disengagement from gangs. Justice Quarterly, 36(1), 31–58. doi: 10.1080/07418825.2017.1357743.

30. Robinson, G., McLean, R., & Densley, J. (2019). Working county lines: child criminal exploitation and illicit drug dealing in Glasgow and Merseyside. International Journal of Offender Therapy and Comparative Criminology, 63(5), 694–711. doi: 10.1177/0306624X18806742.

29. McLean, R., Deuchar, R., Harding, S. & Densley, J. (2019). Putting the ‘street’ in gang: place and space in the organization of Scotland’s drug selling gangs. The British Journal of Criminology, 59(2), 396–415. doi: 10.1093/bjc/azy015.

28. Van Hellemont, E. & Densley, J. (2019). Gang glocalization: how a global mediascape creates and shapes local gang realities. Crime, Media, Culture, 15(1), 169–189. doi: 10.1177/1741659018760107.

27. Peterson, J. & Densley, J. (2018). Is Crisis Intervention Team (CIT) training evidence-based practice? A systematic review. Journal of Crime and Justice, 41(5), 521–534. doi: 10.1080/0735648X.2018.1484303.

26. Eckberg, D., Densley, J. & Dexter, K. (2018). When legend becomes fact, tweet the legend: information and misinformation in the age of social media. Journal of Behavioral and Social Sciences, 5(3), 148–156. ISSN: 2375-8899.

25. McLean, R., Robinson, G. & Densley, J. (2018). The rise of drug dealing in the life of the North American street gang. Societies, 8(3), 90. doi: 10.3390/soc8030090.

24. Lauger, T. & Densley, J. (2018). Broadcasting badness: violence, identity, and performance in the online gang rap scene. Justice Quarterly, 35(5), 816–841. doi: 10.1080/07418825.2017.1341542.

23. Densley, J., McLean, R., Deuchar, R. & Harding, S. (2018). An altered state? Emergent changes to illicit drug markets and distribution networks in Scotland. International Journal of Drug Policy, 58, 113–120. doi: 10.​1016/​j.​drugpo.​2018.​05.​011.

22. Johnson, A. & Densley, J. (2018). Rio’s new social order: how religion signals disengagement from prison gangs. Qualitative Sociology, 41(2), 243–262. doi: 10.1007/s11133-018-9379-x.

21. Pyrooz, D. & Densley, J. (2018). On public protest, violence, and street gangs. Society, 55(3), 229–236. doi: 10.1007/s12115-018-0242-1.

20. McLean, R., Densley, J. & Deuchar, R. (2018). Situating gangs within Scotland’s illegal drugs market(s). Trends in Organized Crime, 21(2), 147–171. doi: 10.1007/s12117-017-9328-1.

19. Densley, J. & Peterson, J. (2018). Group aggression. Current Opinion in Psychology, 19, 43–48. doi: 10.1016/j.copsyc.2017.03.031.

18. Densley, J., Hilal, S., Li, S. & Tang, W. (2017). Homicide-suicide in China: an exploratory study of characteristics and types. Asian Journal of Criminology, 12(3), 199–216. doi: 10.1007/s11417-016-9238-1.

17. Storrod, M. & Densley, J. (2017). ‘Going viral’ and ‘Going country’: the expressive and instrumental activities of street gangs on social media. Journal of Youth Studies, 20(6), 677–696. doi: 10.1080/13676261.2016.1260694.

16. Hilal, S., Densley, J. & Jones, D. (2017). A signaling theory of law enforcement hiring. Policing & Society, 27(5), 508–524. doi: 10.1080/10439463.2015.1081388.

15. Peterson, J. & Densley, J. (2017). Cyber violence: what do we know and where do we go from here? Aggression and Violent Behavior, 34, 193–200. doi: 10.1016/j.avb.2017.01.012.

14. Whittaker, G., Norton, J., Densley, J. & Bew, D. (2017). Epidemiology of penetrating injuries in the United Kingdom: a systematic review. International Journal of Surgery, 41, 65–69. doi: 10.1016/j.ijsu.2017.03.051

13. Densley, J., Adler, J., Zhu, L. & Lambine, M. (2017). Growing Against Gangs and Violence: findings from a process and outcome evaluation. Psychology of Violence, 7(2), 242–252. doi: 10.1037/vio0000054.

12. Densley, J. (2016). 街头帮派中的性暴力和性剥削 [Sexual violence and child exploitation in street gangs; translation by Ni Fe]. 青少年犯罪问题 [Issues on Juvenile Crime and Delinquency], 35(3), 114–120. doi: CLI.A.1213760.

11. Pyrooz, D. & Densley, J. (2016). Selection into street gangs: signaling theory, gang membership, and criminal offending. Journal of Research in Crime and Delinquency, 53(4), 447–481. doi: 10.1177/0022427815619462.

10. Grund, T. & Densley, J. (2015). Ethnic homophily and triad closure: mapping internal gang structure using exponential random graph models. Journal of Contemporary Criminal Justice, 31(3), 354–370. doi: 10.1177/1043986214553377.

9. Densley, J. & Stevens, A. (2015). ‘We'll show you gang’: the subterranean structuration of gang life in London. Criminology & Criminal Justice, 15(1), 102–120. doi: 10.1177/1748895814522079.

8. Densley, J., Cai, T. & Hilal, S. (2014). Social dominance orientation and trust propensity in street gangs. Group Processes & Intergroup Relations, 17(6), 763–779. doi: 10.1177/1368430214533161.

7. Densley, J. (2014). It’s gang life, but not as we know it: the evolution of gang business. Crime & Delinquency, 60(4), 517–546. doi: 10.1177/0011128712437912.

6. Hilal, S., Densley, J., Li, S. & Ma, Y. (2014). The routine of mass murder in China. Homicide Studies, 18(1), 83–104. doi: 10.1177/1088767913505092.

5. Hilal, S., Densley, J. & Zhao, R. (2013). Cops in college: police officers’ perceptions of formal education. Journal of Criminal Justice Education, 24(4), 461–477. doi: 10.1080/10511253.2013.791332.

4. Densley, J. (2012). Street gang recruitment: signaling, screening and selection. Social Problems, 59(3), 301–321. doi: 10.1525/sp.2012.59.3.301.

3. Grund, T. & Densley, J. (2012). Ethnic heterogeneity in the activity and structure of a black street gang. European Journal of Criminology, 9(4), 388–406. doi: 10.1177/1477370812447738.

2. Densley, J. (2012). The organisation of London’s street gangs. Global Crime, 13(1), 42–64. doi: 10.1080/17440572.2011.632497.

1. Densley, J. (2011). Ganging up on gangs: why the gang intervention industry needs an intervention. British Journal of Forensic Practice, 13(1), 12–23. doi: 10.5042/bjfp.2011.0046.


Densley, J. (2020, Jun. 4). We need radical, systemic change in Minnesota policing. Star Tribune.

Peterson, J. & Densley, J. (2019, Dec. 30). Why do people attack places of worship? Here’s what we know from our mass shootings database. Los Angeles Times.

Peterson, J. & Densley, J. (2019, Nov. 14). There is no single profile of a mass shooter. Our data show there are five types. Los Angeles Times.

Peterson, J. & Densley, J. (2019, Oct. 9). What school shooters have in common. Education Week.

Densley, J. & Pyrooz, D. (2019, Sept. 4). Our society can rewrite the gun-violence script. Star Tribune.

Densley, J. & Peterson, J. (2019, Sept. 1). We analyzed 53 years of mass shooting data. Attacks aren’t just increasing, they’re getting deadlier. Los Angeles Times.

Peterson, J. & Densley, J. (2019, Aug. 4). We have studied every mass shooting since 1966. Here’s what we’ve learned about the shooters. Los Angeles Times.

Densley, J. (2019, Jun. 11). Making sense of senseless knife crime. Palgrave MacMillian's #SocSciMatters.

Peterson, J. & Densley, J. (2019, June 7). School shootings: What administrators need to know. Minnesota Association of School Administrators, The Leaders Forum.

Peterson, J. & Densley, J. (2019, May 9). Colorado shooting eerily recalls Columbine massacre. The Conversation.

  • Reprinted as "Columbine created the script school shooters now follow" in Fatherly.
  • Nationally syndicated, including Chicago Tribune, Houston Chronicle, Philadelphia Inquirer, San Francisco Chronicle, Yahoo!.

Peterson, J. & Densley, J. (2019, May 2). University of North Carolina at Charlotte shooting has these things in common with other campus shootings. The Conversation.

Peterson, J. & Densley, J. (2019, Apr. 17). How Columbine became a blueprint for school shooters. The Conversation.

  • Nationally syndicated, including Chicago Tribune, Houston Chronicle, Philadelphia Inquirer, San Francisco Chronicle.
  • Reprinted as "School shootings didn’t start in 1999 at Columbine. Here’s why that disaster became a blueprint for other killers and created the 'Columbine generation'" in The Washington Post.

Densley, J. & Peterson, J. (2019, Mar. 18). Terrorism is a performance. Don't watch. Star Tribune.

Densley, J. & Peterson, J. (2019, Feb. 21). We can do more to prevent mass workplace shootings like Aurora, Illinois. USA Today.

Peterson, J. & Densley, J. (2019, Feb. 8). School shooters usually show these signs of distress long before they open fire, our database shows. The Conversation.

Whittaker, A. & Densley, J. (2019, Jan. 10). London’s gangs have changed, and it's driving a surge in pitiless violence. The Guardian.

Densley, J. & Jones, D.S. (2018, Dec. 21). Want better gun control? Win over the NRA's core members. HuffPost.

Peterson, J. & Densley, J. (2018, Dec. 19). Editorial counterpoint: preventing mass school shootings? Here's a key first step. Star Tribune.

Densley, J. & Storrod, M. (2018, Nov. 29). Youth violence: rise could be linked to British people’s growing distrust of authority. The Conversation.

Robinson, G., Densley, J. & McLean, R. (2018, Oct. 21). County lines: the dark realities of life for teenage drug runners. The Conversation.

Pyrooz, D. & Densley, J. (2018, Jul. 5). Is gang activity on the rise? A movement to abolish gang databases makes it hard to tell. The Conversation.

McLean, R. & Densley, J. (2018, Jun. 23). Agenda: drug dealers know no limits to profit from the misery they cause. The Herald.

Peterson, J. & Densley, J. (2018, Mar. 23). Police crisis intervention training: we need a new paradigm, not a new building. MinnPost.

Peterson, J. & Densley, J. (2018, Feb. 16). Why the usual approach to school security isn't working. CNN.

Densley, J. & Osamoh, S. (2017, Nov. 13). How to stop violence in places of worship. MinnPost.

Densley, J. (2017, Oct. 20). Responses to normalizing violence and the New York Times article ‘waiting for a perfect protest?’. Institute for Communitarian Policy Studies at George Washington University.

Densley, J. (2017, Oct. 16). ISIS is losing the propaganda war. MinnPost.

Pyrooz, D. & Densley, J. (2017, Sept. 17). To deal with Antifa, designate it a street gang. The Wall Street Journal.

Peterson, J. & Densley, J. (2017, Aug. 23). How social media sends extremism into overdrive. CNN.

Densley, J. & Peterson, J. (2017, Jun. 21). Verdict in police shooting of Philando Castile: the fear defense should have us all afraid. Star Tribune.

Peterson, J. & Densley, J. (2017, Apr. 19). Why the trend of posting gruesome acts online? Star Tribune.

Densley, J. & Olson, J. (2016, Jul. 13). A blueprint for better policing in Minnesota. MinnPost.

Densley, J. (2016, Jul. 11). It’s time to rethink Minnesota's system of police education and training. MinnPost.

Densley, J. (2016, Jul. 8). Minnesota's cops are educated but unprepared. Star Tribune.

Densley, J. (2016, Apr. 29). To Minnesota sports fans, from an Englishman: Don't stop believing. MinnPost.

Densley, J. (2016, Jan. 6). Protest movements, guns, and double standards in America. Star Tribune.

Densley, J. & Hilal, S. (2015, Sept. 15). Murder-suicide in Greenwood: making sense of a senseless crime. Star Tribune.

Densley, J. & Jones, D. (2015, Jun. 15). Black lives lost: a genocide from within. Star Tribune.

Densley, J. (2015, May 13). Guns don’t kill people—but they do get people killed. MinnPost.

Densley, J. (2014, Oct. 7). ISIS: The street gang on steroids. CNN.

Densley, J. & Hilal, S. (2014, Mar. 7). Mass murder at Kunming train station: propaganda by deed. MinnPost.

Densley, J. (2013, May 25). My view: Lee Rigby killer No2 was knifed in neck at a crack den aged just 16. The Sun.

Densley, J. (2013, May 24). What London gangs can teach us about London terrorists. MinnPost.

Densley, J. (2013, Mar. 8). So, what will actually work to reduce gun violence? MinnPost.

Densley, J. (2013, Feb. 28). After Sandy Hook, ‘zero-tolerance’ policies are making schools less safe. MinnPost.

Densley, J. (2012, Oct. 30). Why jailing gang bosses causes MORE violence. The Sun.


Urbanik, M-M., Roks, R., Storrod, M.L. & Densley, J. (2020). Ethical and methodological issues in gang ethnography in the digital age: lessons from four studies in an emerging field. In C. Melde and F. Weerman (Eds.), Gangs in the era of internet and social media. Springer.

Lauger, T., Densley, J. & Moule, R. (2020). Social media, strain, and technologically-facilitated gang violence. In A. Bossler & T. Holt (Eds.), The Palgrave handbook of international cybercrime and cyberdeviance. Palgrave Macmillan.

Densley, J. (2020). Collective violence online: when street gangs use social media. In C. A. Ireland, M. Lewis, A. C. Lopez & J. L. Ireland (Eds.), The handbook of collective violence: current developments and understanding (pp. 305–316). Routledge.

Densley, J. (2019). Crips. In R. D. Morgan (Ed.), The SAGE encyclopedia of criminal psychology (pp. 331–335). Sage.

Densley, J. (2018). Gang joining. In H. Pontell (Ed.), Oxford research encyclopedia of criminology and criminal justice. Oxford University Press.

Densley, J. (2018). ‘A citadel of crime’: St. Paul, Minnesota, and the O’Connor system. In J. Windle, J. Morrison, A. Winter, & A. Silke (Eds.), Historical perspectives on organised crime and terrorism (pp. 17–36). Routledge.

Irwin-Rogers, K., Densley, J. & Pinkney, C. (2018). Gang violence and social media. In J. L. Ireland, P. Birch, & C. A. Ireland (Eds.), The Routledge international handbook of human aggression: Current issues and perspectives (pp. 400–410). Routledge.

Densley, J. (2018). The path less traveled: path analysis and the psychology of gang members. SAGE Research Methods Cases, 2. doi: 10.4135/9781526431660.

Densley, J. (2017). Street gangs. In J. Stein (Ed.), Reference module in neuroscience and biobehavioral psychology. Elsevier. doi: 10.1016/B978-0-12-809324-5.05181-6.

Densley, J. & Peterson, J. (2016). Aggression between social groups. In B. J. Bushman (Ed.), Aggression and violence: A social-psychological perspective (pp. 275–289). Routledge.

Densley, J. & Jones, D. (2016). Pulling levers on gang violence in London and St. Paul. In C. Maxson & F-A. Esbensen (Eds.), Gang transitions and transformations in an international context (pp. 291–305). Springer.

Densley, J. (2015). Joining the gang: a process of supply and demand. In S. H. Decker & D. C. Pyrooz (Eds.), The handbook of gangs (pp. 235–256). Wiley.

Densley, J., Davis, A. & Mason, N. (2013). Girls and gangs: preventing multiple perpetrator rape. In M. Horvath & J. Woodhams (Eds.), Handbook on the study of multiple perpetrator rape: A multidisciplinary response to an international problem (pp. 255–281). Routledge.

Trade Journals

Densley, J., Sethuraju, R. & Waddell, C. (2019, March 13). Using documentary film to examine implicit bias, procedural justice, and racial reconciliation. Police Chief.

Densley, J. & Stevens, A. (2017). Gang talk: fact and fiction in London street gang careers. Sociology Review, 26(3), 8–10.

Hilal, S. & Densley, J. (2015). The right person for the job: police chiefs discuss the most important commodity in law enforcement. FBI Law Enforcement Bulletin, 84(10).

Green, J. & Densley, J. (2014). Pell Grant fraud awareness: White collar crime challenges. FBI Law Enforcement Bulletin, 83(2).

Hilal, S. & Densley, J. (2013). Higher education and local law enforcement. FBI Law Enforcement Bulletin, 82(5).

Hilal, S., & Densley, J. (2012). Is law enforcement prepared for the new normal of protest? Minnesota Police Chief, 32(4), 19–22.

Densley, J. (2012). Gangs: cross-cultural comparisons. Minnesota Police Chief, 32(1), 17–18.

Densley, J. & Mason, N. (2011). The London riots: a gang problem? Policing Today, 17(2), 14–15.

Davis, A., & Densley, J. (2011). Life cycle. Police Review, 119(6146), 16–17.

Davis, A., & Densley, J. (2011). Gang warfare. Police Review, 119(6145), 16–17.

Densley, J. (2011). The undercover corporation. Exposition, 7, 4–8.

Mason, N., Densley, J., & Davis, A. (2011). Children killing children. Policing Today, 17(1), 15–17.

Densley, J., & Mason, N. (2010). Growing against gangs. Pennant, 153(1), 31–2.


Peterson, J. & Densley, J. (2019). The Violence Project database of mass shootings in the United States, 1966-2019. The Violence Project.

Densley, J. & Peterson, J. (2017). Gun violence in America. The Violence Project.

Book Reviews

Densley, J. (2016). Review of the book The history of street gangs in the United States: Their origins and transformations, by J. C. Howell. Criminal Law and Criminal Justice Books, 6(1).

Densley, J. (2015). Review of the book The social order of the underworld: How prison gangs govern the American penal system, by D. Skarbek. Global Crime, 16(2), 162–165. doi: 10.1080/17440572.2014.999453.

Densley, J. (2014). Review of the book The gang and beyond: Interpreting violent street worlds, by S. Hallsworth. Criminology & Criminal Justice, 14(3), 368–370. doi: 10.1177/1748895814531866.