Covert policing, ranging from surveillance to undercover operations, include short-term operations and long-term infiltrations. In evaluating the role requirements of an undercover officer the nature and degree of any potential stress will largely depend on the nature of the deployment. While all undercover operations inevitably involve potential role strain, the longer the operation the greater the likely extent of that strain. The possible stressors faced by undercover officers has three main sources: (1) agent-supervisor relationship; (2) role requirements; and (3) strain on family and social relationships. If an officer is working on his/her own, there is the inherent risk of loneliness, leading to the additional risk of 'friendships' with suspects. Undercover officers also experience emotional discomfort by the fear of discovery, whether the threat is real or imagined. Ideally, any psychological management should be at the level of monitoring welfare and preventing problems from developing.