Covert surveillance and informer handling
Criminal investigation is the process undertaken to establish whether an act, intention to act or omission may be labelled a crime and, if it is so labelled, the collection of evidence to determine those responsible and how they will be dealt with in the criminal justice system (Clark 2004). There are two broad categories of investigative processes – namely, reactive and proactive. To these categories should be added a third area of activity: intelligence gathering that is not part of an investigative strategy but that is ostensibly subject to similar legal controls. All investigation consists of the gathering of information and, for policy reasons, investigators seek to separate that which they label intelligence from that which they label evidence. It is because of the tensions that exist between these two types of information that the third category of investigative process has emerged. These categories are often interchangeable and should be viewed as overarching styles, comprising a range of investigative techniques and strategies.