Criminologists James Densley and Jillian Peterson have spent the a decade studying hundreds of mass shootings. They are co-founders of The Violence Prevention Project, a Minnesota-based nonprofit that researches mass violence and pathways to prevention. "These are not young people who are criminal masterminds,” says Densley. "These are crimes that are rooted in despair.” Through interviews with mass shooters and people who knew them, Densley and Peterson say they've identified recurring patterns: early trauma, abuse in the home, chronic bullying, and easy access to firearms. Many shooters, they say, were also influenced by online communities that reinforced violent thinking. #schoolshootings #criminology #violenceprevention