James Densley (born April 13, 1982) is a British-American sociologist and Professor of Criminal Justice at Metropolitan State University. Densley has published extensively on street gang issues and has been described as "among the most accomplished rising leaders of modern gang research in criminology." Densley is best known for his ethnography of gang life in London, England, and his applications of economic signalling theory to gang membership. Densley's research examines group processes in gangs and compares gangs with other violent collectives such as hate groups and terror groups. He once compared the Islamic State to a “street gang on steroids”. Densley writes about the “glocalisation” of gang culture, cyber violence, and the role of rap music and social media in gang violence. He is also known for his research into mass shootings. Densley is a TEDx speaker and has written for CNN, The Conversation, The Guardian, The Herald, HuffPost, Los Angeles Times, MinnPost, Salon, StarTribune, USA Today, and The Wall Street Journal on a range of public issues, including gangs and gang responses, gun violence, knife crime, drug sales, school shootings, and violent extremism. He has appeared on CBS This Morning, CNN Tonight with Don Lemon, Viceland's Black Market: Dispatches with Michael K. Williams, and on local news to comment on criminal justice issues, including police use of force and law enforcement education and training.