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SIO Corner: SIO's M.I. Initial Actions

In a Major Incident there are many questions the SIO must answer and steps they must take initially to set up a sound and robust investigation base ........

In this series we look at various aspects of life as an SIO. This includes the necessary skill sets for the successful SIO, the management of serious crime investigation and specific elements of investigative practice from initial response through crime scene examination and investigative strategies to dealing with suspects and the media. The articles are excerpts from the 2nd edition of Blackstone's, the 'Senior Investigating Officers' Handbook', written by two highly experienced SIOs (see 'About the Authors' at the end of the article).

SIO—Initial Actions and Response

The SIO is rarely one of the first officers to attend the crime scene and is normally notified after a host of other staff and supervisors have attended, taken action, and made important decisions. Therefore there is a lot of information an SIO has to catch up on in order to take effective command of the investigation. The first contact will usually be by telephone, so good, clear communications are vital.

If the SIO is contacted in the middle of the night or at some other awkward moment, a good practical tip is to get the caller to ring back.

This allows time to gather thoughts, become focused, and/or generally get completely ready to deal with the caller properly. Another useful point is to ensure that the person who contacts is someone who knows the full facts; time and energy are important and should not be wasted by having to repeat the process.


If there is pandemonium and chaos the SIO must demonstrate professionalism and composure by competently bringing matters under control. This is precisely what SIOs are known and respected for, and good at—using their core skills and attributes by remaining COOL, CALM and DETACHED and sending out a clear statement of intent as to how they are going to lead the investigation.

What must be clearly understood is that as soon as the SIO is notified and called upon to become involved they are already assuming command of the investigation. By reviewing, checking, and giving instructions, the process has already begun of taking ownership of the investigation. This is true even though it may be some time before the SIO can physically attend at the scene, the police station, or an RV point.

It is accepted that certain things may happen while en route that may be outside their control because they are happening in ‘fast time’ and at a distance. Also there may be other (eg silver) commanders who are in charge of other aspects of the incident who are outside the control of the SIO, eg if the fire service is extinguishing a large fire or a police silver commander is dealing with major public disorder or a ‘crime in action’ type incident. Nonetheless, the SIO must accept responsibility for and take command of the criminal investigation element of the incident or operation at the earliest opportunity and begin controlling that aspect of the incident.


1. The SIO, if unable to reach the crime scene immediately, should confirm who at that time is in command and control of the incident (not investigation because that is the SIO’s responsibilty). All directions or instructions given should be recorded, making it abundantly clear what is required. Until the SIO attends the scene the senior detective or uniform supervisor will be making fast-time decisions and should always keep the en route SIO informed of any developments as soon as practicable via communications link (eg mobile telephone or radio).

2. Verbal instructions may be more prone to misinterpretation than written ones, particularly in highly pressured working environments. All instructions must be given as clearly as possible and repeated back, with the SIO keeping an accurate record of what they have been told and the actions they have raised, who to and when (ie the makings of an initial ‘paper’ action management system, see Appendix B).

3. The process of reviewing and updating fast-track actions should commence as soon as possible. These must be well founded, particularly if based upon uncorroborated verbal accounts of witnesses.

4. The SIO is responsible for bringing order to the many activities that have been initiated during the initial response. If not brought under control, these activities run the risk of generating further confusion and important evidence recovery opportunities could be lost. At the very outset a fresh notebook for keeping notes relating to the enquiry should be commenced, contemporaneously recording:
• date and time notified and by whom;
• means of notification (eg phone or in person);
• full details of incident and the victim(s), using the 5 × WH + H method and details of what action has been taken so far;
• all fast-time instructions and tasks given;
• initial policy decisions.

The same notebook should continue to be used throughout to log all the actions, decisions, and relevant information received. Initially, any policy decisions can be recorded in it, together with times and dates, although these will later need to be formally transferred into an official policy file. The SIO needs to remain calm, confident, and be totally objective. Important instructions must be given to the person who is currently in charge. These must be recorded, timed, and dated in the notebook, together with important contact numbers of those at the scene whom the SIO may need to keep in close contact with.

It is useful to keep a separate list and running log of important contact names and telephone numbers rather than having to thumb through pages of notes to find a valuable number that has been written in amongst something else. A printed table kept on a clipboard and readily available is always useful. It may look as simple as the following table.


The SIO should:

• begin assuming command as soon as the first notification of an incident is received;

• be fully briefed before arriving at the scene, whilst en route, and again on arrival. It is best to stipulate when and how often they should be contacted and updated. This is often a critical time as there are risks from lack of continuity and even temporary loss of direction and momentum if any handover is not managed properly;

• conduct all briefings out of earshot of witnesses, relatives, and friends of any victims, the public, and the media;

• use good note-taking to slow down and set a calmer tone for subsequent events at and around the crime scene. It ensures that attention is paid to precise details that should be delivered to the SIO in a manner that allows them to be recorded coherently;

• preferably to ask questions using the 5 × WH + H method to elicit relevant information. If the caller is left to deliver facts without selective and structured questioning, the briefing may become disjointed and more difficult to follow; any notes recorded will also be more difficult to make sense of;

• soon begin gathering initial thoughts such as ‘what are we dealing with?’. An early assessment will trigger useful thought processes, eg what type or category of crime it is, what the motive is, any early investigative strategies, theories, and managerial considerations.

It is sensible and good practice to appoint an early staff officer and/or loggist to assist. These become an invaluable asset to the busy SIO and can relieve a lot of the work and heavy demands, particularly in ensuring all policy decisions and information received plus actions issued are recorded correctly and contemporaneously.

Once appointed they should stay by the side of the SIO at all times, and can have other responsibilities such as fielding non-urgent calls and writing out details of initial decisions in the policy log.

Early thoughts should be given to appointing other key people and resources who will be needed fairly quickly, for example:

Deputy SIO,

Crime Scene Manager,
Cordon Supervisor,
House-to-House Enquiries Manager,
Exhibits Officer,
Family Liaison officer(s),
Incident Room accommodation and staff,
Outside enquiry teams, etc.

This is the formation of an initial investigation and management team.

Where and how to get these important resources is always going to be challenging, yet extremely important.

A comprehensive SIO aide-memoir checklist is available.

Attendance at the Scene or Police Station?

An early decision must be made as to where the SIO is going to attend, which may be at the scene RV point, a nearby police station, or some other suitable place.

If the scene is indoors and well protected, there is an opportunity for the SIO to attend at a station which has the advantage of being a better place at which to receive a full and comprehensive briefing, examine any relevant data and maps/plans, and make fuller preparation.

It is also an ideal point to meet and brief key people who may accompany the SIO to the scene, such as a pathologist or crime scene manager.

If, however, there is an outdoor scene then the SIO will probably not wish to create any delay in attendance at the RV point to get everything under their full control, such as arranging scene preservation and examination to their satisfaction, etc.

If it is a high-profile incident, the SIO must get to the scene and take control as soon as possible, making themselves highly visible so people can clearly see who and where the SIO is and demonstrating good leadership qualities.

This is also one way of applying the ABC principle and ensuring nothing is assumed or taken at face value and that everything is properly checked—for example making sure everyone’s details at the scene have been obtained and that all vehicle numbers have been fully recorded.

Importantly, the sight of an SIO turning up at the crime scene will boost the morale of staff and make everyone aware of exactly who is in charge.

Note: It may also be worth stipulating in advance who the SIO wishes to see and meet when they arrive (eg a full briefing and walkthrough the scene by the senior officer/detective who has been in charge).

Health and Safety Considerations

Initial response staff who attend at crime scenes may have to face a range of hazards that, because of their spontaneity, require dynamic risk assessments. Examples of these include:

• dangerous suspects and/or volatile crowds or individuals;
• liquid blood and body fluid samples;
• items stained with blood or other body fluids;
• items infested with parasites;
• drugs and drug paraphernalia, eg syringes;
• hazardous chemicals;
• explosives, improvised explosive devices (IEDs), biological, radiological, and nuclear agents;
• unsafe buildings or materials;
• firearms and ammunition;
• sharp items and weapons;
• difficult terrain or dangerous environment and weather;
• disease and poison risks.

Generic risk assessments should exist for attendance at crime scenes. However, given the above, it is essential wherever possible that appropriate advice is sought and personal protective clothing is worn when required.

In addition to protecting the individual this minimizes the possibility of contamination. At a major or serious crime scene, once cordons are in place standard protection consists of a scene suit with hood up, face mask, overshoes, and protective gloves.

Next week we conclude the Initial Response of the SIO with a quick look at Firearms Incidents and a Conclusion before we move on to the management of the Crime Scene.

About the Authors: Detective Superintendent Tony Cook was a CID officer with Greater Manchester Police for over 31 years until his retirement in 2009. During his time as an SIO, he led a number of high profile investigations including operations into gangland violence at Moss Side, the Bolton murder of a teenage girl in 2002, and the Denton strangling case. He was a trained assessor for promotion and a qualified Authorising Officer under RIPA. Tony received 14 commendations and a first-class BSc Honours degree in social sciences and a Diploma in Social Policy & Criminology from the Open University. Andy Tattersall, formerly Detective Superintendent in Greater Manchester Police on the Force Major Incident Team, retired in 2007 after 33 years service and became the first ever Support Staff SIO in charge of a new Homicide Support Unit. With over 29 years in CID at all ranks Andy received the Homicide Working Group National Award for his Outstanding Achievement in the Field of Homicide in November 2006.

To see more details about the Senior Investigating Officers' Handbook, or to purchase a copy, click here.


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