With increased media coverage of school violence, communities and schools have hired school resource officers (SROs) in an attempt to reduce the violence. These SROs often have a variety of duties and training depending on a variety of factors both related and unrelated to school crime and violence prevention. These may include typical school staff duties such as mentoring but frequently are more similar to those of law enforcement personnel, such as patrolling. In this article, we review the literature on SROs, identifying their common roles as well as the benefits and drawbacks to their presence in public schools in the United States. The literature suggests that there is a complicated relationship between SROs and crime and violence prevention in schools, including different outcomes for different populations of students. Based on our review of the literature, we recommend changes regarding the use of SROs in public schools for policy makers, school practitioners, and researchers.