Harfield, Clive., <br/><br/>
Covert investigation / 
Clive Harfield, MSc, LLM, MA, MPhil, PhD and Karen Harfield, BSc (Hons) ; with a foreword by Professor John Grieve, CBE, QPM. 
 - Fourth edition. 
 - xxxvii, 265 pages :  illustrations ;  24 cm. 
 - Blackstone's practical policing .
<br/><br/>Includes bibliographical references and index. 
<br/><br/>Navigating a moral minefield -- Statutory principles in covert investigation -- Authorization and governance -- Understanding the operating environment -- Managing covert investigation -- Directed surveillance --- Intrusive surveillance -- Interference with property or wireless telegraphy and entry onto land -- Covert investigation and computers -- Examining mobile phones -- Commmunications data -- Interception of communications -- Covert human intelligence sources -- Covert investigation abroad -- What does good covert investigation look like? 
<br/><br/><label>ISBN: </label>9780198743293 
<br/><br/><label>LCCN: </label>2016931036 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Undercover operations--Law and legislation--Great Britain.<br/>Police patrol--Surveillance operations.--Great Britain
<br/><br/><label>LC Class. No.: </label>KD8335  / .H37 2016