Researchers of crime prevention have in the last decades noticed significant changes in societal responses to criminal justice, such as privatisation of security governance and informal social control exerted by organisations beyond the justice system. Researchers have also highlighted that a growing number of school staff experience their work as surpassing the demands associated with a traditional school environment, becoming more like the work of police officers, social workers, parents, or friends than to that of teachers and educators. This ethnographic study explores the previous statements by focusing on the experiences of school staff working with pupils who have issues with alcohol or drug use, drug trafficking or other criminal behaviour. Based on 36 semi-structured interviews with teachers, school nurses, counsellors, and social workers, the study suggests that their work requires higher emotional investment than a traditional school environment does. The staff take much responsibility regarding (informal) crime prevention efforts and are thus part of an informal culture of control. The findings suggest conflicting demands regarding their work tasks and emotional commitment: on the one hand to providing emotional support and ensuring a good educational environment for all pupils, and on the other hand to act as informal police officers or supervisors of pupils with addictions. The study describes how emotions and emotional labour are used to handle these conflicting demands. It also demonstrates the need for developing teacher education and clear-cut policies regarding the crime preventative role of high schools in Sweden, as staff members experienced confusion, frustration, and ad-hoc solutions in the absence of a streamlined approach.