Handbook of Gun Violence covers a variety of subjects and disciplines related to gun violence research. The first section provides an updated overview of the prevalence of gun violence, including a dedicated section to the surge in violence during the COVID-19 pandemic. The second section covers biopsychosocial risk and protective factors for violence, including genetics, psychopathology, neurocognitive function, and community influences. The last section reviews options for Gun violence prevention and intervention, including treatments for youth delinquency and violence and antisocial behavior.