for a defined period of time. If an agent is able to resist interrogation for a defined period of time, the odds improve that other members of the network can be alerted to the compromise. Case officer A case officer is an intelligence officer who is a trained specialist in the management of agents and agent networks. Case officers manage human agents and human intelligence networks. Case officers spot potential agents, recruit prospective agents and train agents in tradecraft. Case officers emphasize the elements of tradecraft that enable the agent to acquire needed information, and enable the case officer to communicate with and supervise the agent. Most importantly, case officers train agents in methods of avoiding detection by host nation counter-intelligence organizations. Agents, spotting, and recruitment By definition, an "agent" acts on behalf of another, whether another individual, an organization, or a foreign government. Agents can be considered either witting or unwitting, and in some cases, willing or unwilling. Agents typically work under the direction of a principal agent or a case officer. When agents work alone, and are not members of an agent network, they are termed "singletons". The identification of potential agents is termed "agent spotting" (also termed "talent spotting"). Identifying potential agents, and investigating the details of their personal and professional lives, involves the granular verification of their bona fides. Such activities can include uncovering personal details that leave potential agents vulnerable to coercion, blackmail, or other inducements, such as sexual approaches. Approaches to potential agents can be multitudinous and considerable time can pass before the potential agent is maneuvered into a position where a recruitment "pitch" can be hazarded. Training Agent training often includes techniques of tradecraft such as clandestine communication, including cryptography, the use of one-time pads, the construction of concealment devices, and the employment of dead drops. Other elements of tradecraft include elicitation, surveillance and countersurveillance, photography and the emplacement of audio devices, sensors, or other transmitters. Case officers generally train agents one at a time, in isolation, including only those elements of tradecraft needed to penetrate the target at hand. Case officers will also teach agents how to develop cover for status, and cover for action, meaning how to establish credible pretexts for their presence and behavior while engaged in collection activities. A well-trained and competent agent can conduct his or her clandestine tasks while under close surveillance, and still evade detection. More