A competent investigator will not rely only on database tools but will have a spectrum of trusted legal contacts and access to privileged index registries, libraries and archives. Some more established agencies have proprietary ‘open-source intelligence’ software which crawls and analyses websites both on the indexed web (found on Google etc) but also the wider ‘deep web’ and its subset referred to as the dark web. There are also databases that synthesise information gathered from other databases. The main quality to look for in an investigator locating people is a deep understanding of the investigation techniques that need to be utilised in order to locate a specific person.