Publications

MacLean, C., & Densley, J. (2023). Police, prosecutors, courts, and the constitution: toward ending the “awful but lawful” era. Springer.

Densley, J., McLean, R., & Brick, C. (2023). Contesting county lines: case studies in drug crime and deviant entrepreneurship. Bristol University Press.

Decker, S., Pyrooz, D., & Densley, J. (2022). On gangs. Temple University Press.

McLean, R., & Densley, J. (2022). Robbery in the illegal drugs trade: violence and vengeance. Bristol University Press.

Peterson, J., & Densley, J. (2021). The Violence Project: how to stop a mass shooting epidemic. Abrams Press. 

McLean, R., & Densley, J. (2020). Scotland’s gang members: life and crime in Glasgow. Palgrave Macmillan. 

McLean, R., Robinson, G., & Densley, J. (2019). 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.

Pyrooz, D., Densley, J., & Leverso, J. (2024). The Oxford handbook of gangs and society. Oxford University Press. 

Densley, J. (2023). The Conversation on guns. Johns Hopkins University Press.

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

Riedman, D., Densley, J., Peterson, J., & Erickson, G. (in press). Noise audit measuring variability in police perceptions of school shooting threats. Homeland Security Affairs.

Pyrooz, D., Densley, J., & Sanchez, J. (in press). Are online opt-in panels viable data sources on hard-to-reach populations? Population and relational inferences on gang membership in the United States. International Criminology.

Pyrooz, D., Densley, J., & Peterson, J. (in press). Direct exposure to mass shootings among American adults. JAMA Network Open. https://doi.org/10.1001/jamanetworkopen.2025.0283.

Peterson, J., & Densley, J. (in press). Exploring the overlap: Suicidal thoughts and homicidal acts among incarcerated offenders. Deviant Behavior. https://doi.org/10.1080/01639625.2024.2443778.

Densley, J., & Peterson, J. (in press). Murder in a time of crisis: a qualitative exploration of the 2020 homicide spike through offender interviews. Journal of Crime and Justice. https://doi.org/10.1080/0735648X.2024.2426502.

Densley, J., MacLean, C., & Hilal, S. (in press). Educating and training culturally competent peace officers: challenges and opportunities of the Minnesota model. Multicultural Learning and Teaching, 19. https://doi.org/10.1515/mlt-2023-0029.

Leverso, J., Densley, J., & Insco, L. (in press). Keeping it real: a signaling theory perspective on authentic claims of gang membership made on social media. Theoretical Criminology. https://doi.org/10.1177/13624806241279280.

Pyrooz, D., & Densley, J. (in press). Pulling back the curtain on the California gang database: evidence of racial, ethnic, and gender disparities among 222 law enforcement agencies. British Journal of Criminology. https://doi.org/10.1093/bjc/azae040. 

Densley, J., Pyrooz, D., & Sanchez, J. (in press). Public perceptions of gangs: an experimental test of nomenclature, race/ethnicity, violence, and organization. Justice Quarterly. https://doi.org/10.1080/07418825.2024.2378703. 

Deuchar, R., Frondigoun, L., Densley, J., & Davidones, C. (in press). Taser use in Scotland: a qualitative study of police officer and community perspectives. European Journal on Criminal Policy and Research. https://doi.org/10.1007/s10610-023-09569-3. 

Pyrooz, D., Densley, J., & Sanchez, J. (2024). Does the public support anti-gang policies and practices and can opinions be swayed? Experimental evidence from a national survey of Americans. Journal of Criminal Justice, 94, 102265. https://doi.org/10.1016/j.jcrimjus.2024.102265.

Peterson, J., Densley, J., Hauf, M., & Moldenhauer, J. (2024). Epidemiology of mass shootings in the United States. Annual Review of Clinical Psychology, 20, 125–148. https://doi.org/10.1146/annurev-clinpsy-081122-010256.

Peterson, J., Densley, J., Riedman, D., Spaulding, J., & Malicky, H. (2024). An exploration of K-12 school shooting threats in the United States. Journal of Threat Assessment and Management, 11(2), 106–120. https://doi.org/10.1037/tam0000215.

Deuchar, R., & Densley, J. (2024). Exploring the intersection of drug addiction and mental ill-health in Scottish prisons: a qualitative study of incarcerated men. Journal of Drug Issues, 54(3), 326–345. https://doi.org/10.1177/00220426231161282. 

Pyrooz, D., Leverso, J., Sanchez, J., & Densley, J. (2024). History, linked lives, timing, and agency: new directions in developmental and life-course perspective on gangs. Annual Review of Criminology, 7, 105–127. https://doi.org/10.1146/annurev-criminol-022222-035715. 

Havard, T., Densley, J., Whittaker, A., & Wills, J. (2023). Street gangs and coercive control: the gendered exploitation of young women and girls in county lines. Criminology & Criminal Justice, 23(3), 313–329. https://doi.org/10.1177/1748895821105151. 

Peterson, J., Densley, J., Spaulding, J., & Higgins, S. (2023). How mass public shooters use social media: Exploring themes and future directions. Social Media + Society, 9(1). https://doi.org/10.1177/20563051231155101. 

Jewett, P., Gangnon, R., Borowsky, I., Peterson, J., Areba, E., Kiragu, A., & Densley, J. (2022). US mass public shootings since Columbine: victims per incident by race and ethnicity of the perpetrator. Preventive Medicine, 162(9), 107176. https://doi.org/10.1016/j.ypmed.2022.107176. 

Peterson, J., Densley, J., Knapp, K., Higgins, S., & Jensen, A. (2022). Psychosis and mass shootings: A systematic examination using publicly available data. Psychology, Public Policy, and Law, 28(2), 280–291. https://doi.org/10.1037/law0000314. 

Rahman, M., McLean, R., Deuchar, R., & Densley, J. (2022). Who are the enforcers? The motives and methods of muscle for hire in West Scotland and the West Midlands. Trends in Organized Crime, 25(1), 108–129. https://doi.org/10.1007/s12117-020-09382-y.

Peterson, J., Erickson, G., Knapp, K., & Densley, J. (2021). Communication of intent to do harm preceding mass public shootings in the United States, 1966–2019. JAMA Network Open, 4(11), e2133073. https://doi.org/10.1001/jamanetworkopen/2021.33073.

Densley, J. (2021). What the lives of mass shooters and gang members can teach us about preventing online hate. Journal of the American Academy of Child and Adolescent Psychiatry, 60(10), S23. https://doi.org/10.1016/j.jaac.2021.07.108.

Van Hellemont, E., & Densley, J. (2021). If crime is not the problem, crime fighting is no solution: policing gang violence in the age of abolition. Journal of Aggression, Conflict and Peace Research, 13(2–3), 136–147. https://doi.org/10.1108/JACPR-12-2020-0561.

Roks, R., Leukfeldt, E. R., & Densley, J. (2021). The hybridization of street offending in the Netherlands. British Journal of Criminology, 61(4), 926–94. https://doi.org/10.1093/bjc/azaa091.

Hyatt, J., Densley, J., & Roman, C. (2021). Social media and the variable impact of violence reduction interventions: re-examining focused deterrence in Philadelphia. Social Sciences, 10(5), 147. https://doi.org/10.3390/socsci10050147.

• Reprinted in Valasik, M., & Reid, S. (2024, Eds.), Research on gang-related violence in the 21st century. MDPI Books.

Peterson, J., Densley, J., & Erickson, G. (2021). Presence of armed school officials and fatal and nonfatal gunshot injuries during mass school shootings, United States, 1980-2019. JAMA Network Open, 4(2), e2037394. https://doi.org/10.1001/jamanetworkopen/2020.37394.

Peterson, J., Densley, J., & Erickson, G. (2020). Evaluation of 'the R-Model' crisis intervention de-escalation training for law enforcement. The Police Journal, 93(4), 271–289. https://doi.org/10.1177/0032258X19864997.

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. https://doi.org/10.1016/j.chb.2020.106403.

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. https://doi.org/10.1177/0011128718794192. 

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. https://doi.org/10.1177/1473225419883706.

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. https://doi.org/10.1177/1473225420902848.

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

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. https://doi.org/10.1007/s10610-019-09408-4.

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. https://doi.org/10.1177/1098611119849646. 

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

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

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

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. https://doi.org/10.1177/0306624X18806742.

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. British Journal of Criminology, 59(2), 396–415. https://doi.org/10.1093/bjc/azy015.

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. https://doi.org/10.1177/1741659018760107.

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.  https://doi.org/10.1080/0735648X.2018.1484303.

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.

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. https://doi.org/10.3390/soc8030090.

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

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. https://doi.org/10.​1016/​j.​drugpo.​2018.​05.​011.

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

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

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

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

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

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. https://doi.org/10.1007/s11417-016-9238-1.

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. https://doi.org/10.1080/13676261.2016.1260694.

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

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. https://doi.org/10.1016/j.avb.2017.01.012.

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. https://doi.org/10.1016/j.ijsu.2017.03.051.

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. https://doi.org/10.1037/vio0000054.

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. CLI.A.1213760.

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. https://doi.org/10.1177/0022427815619462.

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. https://doi.org/10.1177/1043986214553377.

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. https://doi.org/10.1177/1748895814522079.

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

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

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

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. https://doi.org/10.1080/10511253.2013.791332.

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

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. https://doi.org/10.1177/1477370812447738. 

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

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

Peterson, J., & Densley, J. (2025, Jan. 13). Isolation, ‘psychache,’ violence and self-destruction: What research shows. Minnesota Star Tribune.

Densley, J., Peterson, J., & Riedman, D. (2024, Dec. 17). Here’s what is so unusual about the Wisconsin school shooting — and what isn’t. Los Angeles Times.

Peterson, J., & Densley, J. (2024, Sept. 15). Gun violence in Minnesota: what the numbers show. Minnesota Star Tribune.

Densley, J., & Peterson, J. (2024, Sept. 6). Georgia high school shooting shows how hard it can be to take action even after police see warning signs. The Conversation. 

Pyrooz, D., & Densley, J. (2024, Aug. 16). If police want gang databases, they should have to prove their value. Governing.

Pyrooz, D., Densley, J., & Peterson, J. (2024, Apr. 14). The grim legacy of Columbine after 25 years. The Denver Post.

Peterson, J., & Densley, J. (2023, Mar. 28). Crumbley parents lose their appeal. Why that could be a game changer on school shootings. CNN.

Riedman, D., & Densley, J. (2023, Feb. 14). MSU murders: What we know about campus shootings and the gunmen who carry them out. The Conversation. 

Riedman, D., Densley, J., &  Peterson, J. (2023, Feb. 10). Five years after Parkland, school shootings haven’t stopped, and kill more people. The Conversation. 

Peterson, J., & Densley, J. (2023, Jan. 26). We profiled the 'signs of crisis' in 50 years of mass shootings. This is what we found. The New York Times. 

• Spanish translation: "50 años de tiroteos masivos en EE. UU. arrojan una conclusión: hay un problema social que debemos resolver," The New York Times en Español, Feb. 3, 2023.

Densley, J., & Peterson, J. (2023, Jan. 25). Older mass shooters are rare. Here’s how they differ from young assailants. Los Angeles Times.

Peterson, J., & Densley, J. (2023, Jan. 24). Typical mass shooters are in their 20s and 30s – suspects in California’s latest killings are far from that average. The Conversation.

Peterson, J., & Densley, J. (2022, Nov. 22). Rampage at Virginia Walmart follows upward trend in supermarket gun attacks -- here's what we know about retail mass shooters. The Conversation. 

Densley, J., Riedman, D., & Peterson, J. (2022, Oct. 25). With months still to go, 2022 has already seen a record number of school shootings. The Conversation. 

Peterson, J., & Densley, J. (2022, Jun. 24). The 4 risk factors behind someone becoming a mass shooter. Big Think.

Densley, J., & Peterson, J. (2022, Jun. 7). The steps we can take to reduce mass shootings in America. TIME.

• Reprinted in M. Goldthwaite, J. Bizup, & A. Fernald (Eds., 2024). The Norton Reader (16th Ed.). W.W. Norton. 

Densley, J., & Peterson, J. (2022, May 25). What we know about mass school shootings in the US – and the gunmen who carry them out. The Conversation. 

• Reprinted as "What we know about mass school shootings—and shooters—in the U.S." in Scientific American.

Densley, J., & Peterson, J. (2022, May 20). Accused Buffalo mass shooter had threatened a shooting while in high school. Could more have been done to avert the tragedy? The Conversation. 

Densley, J., & Peterson, J. (2022, May 15). Hate is not at the root of most mass shootings. Washington Post. 

Peterson, J., & Densley, J. (2022, May 15). More mass shootings are happening at grocery stores – 13% of shooters are motivated by racial hatred, criminologists find. The Conversation. 

• Reprinted as "Did 'social contagion' spur Buffalo mass shooting?" in The Crime Report.

• Reprinted as "Mass shooters are targeting grocery stores more often" in Daily Beast. 

Decker, S., Pyrooz, D., & Densley, J. (2022, Jan. 20). What is past is prologue: A century of gangs in the United States. North Philly Notes.

Densley, J., & McLean, R. (2022, Jan. 17). Robbery in the illegal drugs trade. Transforming Society.

Riedman, D., Densley, J., &  Peterson, J. (2021, Dec. 20). School closures are costly caution — but are still not enough to prevent tragedies. Star Tribune.

Riedman, D., Peterson, J., & Densley, J. (2021, Dec. 16). Assessing shooting threats is a matter of life or death. Why aren’t experts better at it? Education Week.

Densley, J., Pyrooz, D., & Decker, S., (2021, Dec. 10). The real cultural significance of ‘West Side Story’? It spread powerful myths about gangs. Los Angeles Times.

Pyrooz, D., Densley, J., & Decker, S. (2021, Dec. 9). ‘West Side Story’ may be timeless – but life in gangs today differs drastically from when the Jets and Sharks ruled the streets. The Conversation.

Densley, J., & Peterson, J. (2021, Dec. 7). The powerful message behind charging the parents in the Michigan school shooting. Los Angeles Times.

Densley, J., & Peterson, J. (2021, Dec. 2). School shootings are at a record high this year – but they can be prevented. The Conversation. 

Densley, J., Riedman, D., & Peterson, J. (2021, Nov. 5). The rise in school shooting threats is alarming — and a cry for help. Los Angeles Times. 

Peterson, J., Densley, J., & Riedman, D. (2021, Oct. 8). School shootings are increasing — and changing. Easily accessible guns are to blame. Washington Post.

Riedman, D., Densley, J., & Peterson, J. (2021, Sept. 24). One second from Columbine at Lehigh Acres. Sun-Sentinel. 

Riedman, D., Peterson, J., & Densley, J. (2021, Aug. 23). Students, teachers must feel safe to report school shooting threats. Tennessean.

Densley, J., & Peterson, J. (2021, April 14). Knoxville school shooting serves as stark reminder of a familiar – but preventable – threat. The Conversation.

Peterson, J., & Densley, J. (2021, Mar. 23). Why mass shootings stopped in 2020 and are now roaring back. Los Angeles Times. 

• Spanish translation: ¿Por qué los tiroteos masivos se detuvieron en 2020 - y por qué ahora están volviendo? Los Angeles Times, Mar. 28, 2021.

Densley, J. (2021, Mar. 15). Restoring humanity to juvenile justice is overdue. Star Tribune. 

Peterson, J., & Densley, J. (2020, Dec. 9). US gun violence: too many people have died in 2020 – and COVID played a larger part than you think. The Conversation.

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. 

• Reprinted in Rottenberg, A. T., & Winchell, D. H. (2021). Elements of argument: A text and reader (13th Ed.). Bedford/St. Martin’s.

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

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.

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. 

• 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 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. 

• Reprinted in Stirling, P., De Silva, S., de Meza, L., Geddes, I. & Campbell, C. (2021). Explore PSE: health and wellbeing for CfE, student book. Hodder Education.

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?’. The Communitarian Observer (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.

Peterson, J., & Densley, J. (2026). Gun violence (and mass shootings). In P. Zapf (Ed.), APA Handbook of Forensic Psychology (2nd Ed.). American Psychological Association. 

Densley, J. (2024). Foreword. In M. Rahman, & R. Deuchar (Eds.), Ethics in qualitative criminological research: risks, boundaries, emotions, and reflexivity (pp. viii-x). Routledge.

Pyrooz, D., Densley, J., & Leverso, J. (2024). Introduction to the OUP handbook of gangs and society. In D. Pyrooz, J. Densley, & J. Leverso (Eds.), The Oxford handbook of gangs and society (pp. 1–12). Oxford University Press.

Peterson, J., & Densley, J. (2023). Mass shootings and mental health in the United States: key dynamics and controversies. In Madfis, E., & Lankford, A. (Eds.), All American massacre: the tragic role of American culture and society in mass shootings (pp. 319–336). Temple University Press. 

Densley, J. (2023). US and UK gangs: research, policy and practice. In Andell, P., & Pitts, J. (Eds.), The Palgrave handbook of youth gangs in the UK (pp. 91–110). Palgrave Macmillan.

Densley, J. (2022). Foreword. In R. Deuchar, R. McLean, & C. Holligan, Gangs, drugs and youth adversity: continuity and change (pp. v-vii). Bristol University Press.

Densley, J. (2021). Over-policed and under protected: police violence as a symptom and cause of urban violence in America’s Black communities. In J. Kestenbaum, C. Mahoney, A. Meade, & A. Fuller (Eds.), Public health, mental health and mass atrocity prevention (pp. 71–88). Routledge.

Johnson, A., & Densley, J. (2021). El nuevo orden social de la carcel: religion y desvinculacion de las bandas de las prisones en Rio de Janeiro. In D. Smilde, & H. Pérez Hernáiz (Eds.), Postsecularismo y la religión vivida: aportes desde la sociología cualitativa Norteamericana (pp. 23–52). Abediciones: Universidad Católica Ándres Bello. 

Peterson, J., & Densley, J. (2021). What we’ve learned about mass shooters since 1966. In Rottenberg, A. T., & Winchell, D. H. (Eds.), Elements of argument: A text and reader (13th Ed.). Bedford/St. Martin’s.

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 (pp. 21-41). 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 (pp. 1375–1395). 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. (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.

Densley, J. (2023). In county lines, knife comes at you fast. Fighting Knife Crime, 7, 6–9. 

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

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. (2025). Report to the Minnesota legislature. The Violence Prevention Project Research Center.

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.

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. https://doi.org/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. https://doi.org/10.1177/1748895814531866.