Part 4 125 the investigation is begun. The lead investigator should maintain a logbook, in which he or she records all of the critical, significant and strategic decisions, together with the reasons for them, in full. The logbook should be used to record the progress of the investigation. Examples of the type of decisions that should be recorded in a logbook are: • The identification of someone as a suspect where reasonable suspicion exists; • The decision that there are reasonable grounds to arrest a suspect; • The decision to delay arresting a suspect; • The decision to arrest and detain a suspect, including the name of the arrestee; the time and place of arrest; the reasons for arrest and detention; the place of custody (and possible transfer of the suspect to another location); the time in and out of detention; the identity of the officers involved; and information on the first appearance of the suspect before a judicial authority;138 • The decision to deploy an SIT; • The main lines of enquiry; • The area designated as a crime scene; • The type of forensic examinations requested; and • The decision to offer witness protection. It is often just as important to record why something was not done as it is to record why it was done, including the key facts impacting the decision, in order to put the decision in context. It is also vital to record the decision at the time it was made, or very shortly thereafter. The facts of a situation can change and a decision that was sound when made may appear unsound many months later in court. If the facts and the reasoning were recorded contemporaneously, it is then easier to justify what was decided. As well as serving as a useful memory aid in subsequent legal proceedings, recording the reasons also helps to focus the lead investigator’s mind and ensure that the decisionmaking process is robust and the rationale for the decision is sound. 138 138 Guidebook on Democratic Policing by the Senior Police Adviser to the OSCE Secretary General, op. cit., note 18, p. 33.