Covert investigation /
Harfield, Clive.
Harfield, Karen.
Oxford : Oxford University Press,
2005.
Includes index.
Covert investigation in context -- Directed surveillance -- Intrusive surveillance -- Interference with property or wireless telegraphy and entry onto land -- Covert investigation and computers -- Examining mobile phones -- Communications data -- Interception of communications -- Covert human intelligence sources -- Covert investigation abroad -- Risk management
Undercover operations
Police patrol