Project Summary/Abstract Firearm risks, which includes direct and indirect victimization of firearm violence, firearm violence perpetration, and firearm access and carrying, is an urgent public health issue across the U.S. The death rate from firearm- related injuries among youth aged 15 to 24 stands at 17.7 per 100,000 – the second highest across age groups. Youth experiencing homelessness (YEH) are especially vulnerable to violence. Approximately 4.2 million youth experience homelessness each year. In one study conducted by the PI using data from YEH in 7 major cities across the U.S., over 45% had experienced firearm victimization in their lifetime, 17% had perpetrated firearm violence in their lifetime, and 34% had easy access to a firearm. Virtually nothing is known about individual, social network, and neighborhood environmental characteristics that may be associated with YEH’s firearm violence exposure, access and tendency to carry firearms. Additionally, current interventions (e.g., school-based interventions) are not likely to apply to their homelessness context, nor even reach them. Understanding firearm risks among YEH from a socio-ecological perspective will provide critical information to inform primary and secondary firearm violence prevention strategies for YEH. This proposal is in response to RFA-CE-22-004, Research Grants to Prevent Firearm-Related Violence and Injuries (R01), specifically addressing Objective One (research to improve understanding of firearm injury and inform the development of innovative and promising prevention strategies) that encourages examination of modifiable individual and social environmental factors for firearm violence victimization and perpetration among vulnerable populations. This project will investigate how individual, social network, and neighborhood environmental characteristics are associated with YEH’s firearm risks and examine the role their social network may play in moderating these risks either by attenuating or exacerbating individual and neighborhood influences. In accordance with Funding Option B, this 3-year project will use a cross-sectional survey design to conduct primary data collection using computer-assisted, face-to-face structured interviews from YEH at drop-in centers in Los Angeles County, California and the greater St. Louis, Missouri area. Following previously validated procedures, this study will also employ a novel use of Google Street View to virtually collect block-based environmental data surrounding places where youth experience homelessness. Individual characteristics among YEH will include personal background characteristics (e.g., homeless history, mental health, substance use). Social network compositions will include member types, perceived member norms, and behaviors. Neighborhood environment will include social and physical characteristics as well as overall neighborhood disorder. Such a comprehensive understanding of our most vulnerable, minoritized and histor...