Sanction Detection Rates

The ‘murder rate’ is one way of measuring the effectiveness of the justice system. Another is the percentage of homicides that are ‘cleared up’ – otherwise known as the Sanction Detection Rate.

This means cases where a suspect has been identified but not necessarily convicted of the crime, perhaps because they have been acquitted on the grounds of self defence. A small number of cases are classed as unresolved, such as the murder of Jill Dando (the suspect was first convicted then acquitted several years later following a retrial).

According to the official definition: ‘A sanctioned detection occurs when (1) a notifiable offence (crime) has been committed and recorded; (2) a suspect has been identified and is aware of the detection; (3) the CPS evidential test is satisfied; (4) the victim has been informed that the offence has been detected, and; (5) the suspect has been charged, reported for summons, or cautioned, been issued With a penalty notice for disorder or the offence has been taken into consideration when an offender is sentenced.’

The Metropolitan Police’s list of homicides for January 2006 to September 2011 (issued in September 2011) revealed that 85.2 per cent of the homicides listed had been ‘detected’. Most are sanction detections but there are a few other detections where the suspect committed suicide after carrying out the killing. This figure can potentially change over time as suspects are charged and put on trial.

Another release under the Freedom of information act breaks down the number of sanction detections made every financial year between 2007/08 and 2010/11.

The Sanction Detection Rate (SDR) is therefore 83 per cent for 2007/08, rising to a consistent 93 to 94 per cent for the following three years.

This is a different kind of measurement because it includes detections of cases that took place in earlier years, and therefore the ‘closure rate’ could potentially be higher than 100 per cent. This sounds absurd (See the debate around the announcement that Washington DC had a 94 per cent closure rate for homicide), but it does give an indication of the effectiveness of homicide investigations. The SDR also does not change over time.

Looking at the UK as a whole, the last set of Home Office statistics gave a sanction detection rate of 86 per cent for 2009/2010 and 83 per cent for 2010/11 (the number of homicides rose from 618 to 642, with the number of sanction detections made over the same period falling from 533 to 530).

Perhaps of more interest is the comparison between the sanction detection rates for homicide and other offences including domestic crime, robbery, burglary, sexual offences, gun crime and knife crime.

Homicide has long been prioritised by the police and the justice system, for obvious reasons. It is investigated centrally by a separate ‘Homicide and Serious Crime Command’ rather than by detectives in the respective borough, and can devote large amounts of manpower and money to analysing CCTV footage, mobile phone data and forensic examination.  There are also far fewer cases to concentrate on compared to other offences – for example in 2009/10, the figures show 117 homicides compared to 51,682 domestic offences, 9,930 sexual offences, 33,479 robberies, 92,807 burglaries, 3,460 offences of gun crime and 12,617 of knife crime.

Clearly, it’s a lot harder to get away with murder.

The Waterloo Bag Mystery

Last month the whole country was baffled and enthralled by the inquest into the suspicious death of GCHQ ‘spy’ Gareth Williams, who was found inside a padlocked bag at his home in Pimlico, south London.

The case has chilling echoes of a murder that took place more than 150 years ago. Known as ‘The Waterloo Bridge Mystery’ or ‘The Thames Carpet Bag Mystery’, it too featured a male body inside a locked bag.

The bag in question was found on an ‘abutment’ of Waterloo Bridge by two young men in a rowing along the Thames early one morning in October 1857. Once opened, it revealed 23 bones and a few scraps of flesh. The head, hands, feet and internal organs were missing.

The Waterloo Bridge Mystery
Drawing of The Waterloo Bridge Mystery from the Illustrated Police News

For the next two weeks, as the story played out in the newspapers of the day, the public were both fascinated and appalled by the gruesome details until eventually the police ground to a halt. The only lead was a sighting of an elderly woman carrying the bag on to the bridge the previous night.

Some even suggested that the whole affair was a grisly hoax perpetrated by anatomical students.

The Waterloo Bridge Mystery was ruled a ‘wilful murder’ just over two weeks after the discovery of the body.

By contrast the Gareth Williams case the inquest took place 21 months after the discovery body and ended with the coroner ruling that there was not enough evidence to sustain a finding of ‘unlawful killing’ (the equivalent to the Victorian verdict of ‘wilful murder’).

Both cases became the talk of their day, the subject of gossip and speculation. But there are also many differences. Gareth Williams was an identifiable person. He had a name, a grieving family, friends and colleagues. He had hobbies and interests. Yet somehow the more we found out, the more mysterious his death became.

The victim of the Waterloo Bridge Mystery was never identified. Despite being described by the Times in 1857 as ‘one of the most horrible murders that has ever stained our criminal annals,’ the case is now all but forgotten.

Read the full details of The Waterloo Bridge Mystery

Suspicious and Unexplained

The case of MI6 spy Gareth Williams is one of those rare mysteries that seems to defy all logic. It begins with a body, but it is a body within a locked bag within a locked room. Detectives and scientists have marshaled all their resources in an attempt to work out how it happened yet at the end of it we do not even know the cause of death.

Up until the inquest Gareth Williams’ death was not classed as a homicide for the reason that the police could not even be sure anyone else was involved. It was instead classed as ‘suspicious and unexplained’ (although the case was investigated by the ‘Homicide and Serious Crime Command’, often referred to as the ‘murder squad’).

So how many suspicious and unexplained deaths do the murder squad deal with each year? We put in a Freedom of Information request covering the last five years, and this is what came back:

Financial Year Total S/U Deaths Remains S/U Reclassified as Homicide
2011/12 16 16 0
2010/11 20 11 2
2009/10 28 22 3
2008/09 20 10 5
2007/08 31 16 6

The ‘total s/u deaths’ is the number of suspicious / unexplained deaths referred to the Homicide and Serious Crime Command during that year.

This shows that the Gareth Williams case was just one of 20 suspicious / unexplained deaths in the financial year 2010-2011. It is one of 11 such cases that remain classed as suspicious / unexplained.

Cases are more likely to reclassified as time goes by, which explains the increase in the final column. It is also reassuring to know that the decrease in the number of homicides over the last ten years isn’t explained by an increase in cases classed as suspicious / unexplained.

On the other hand, the families of those whose cases remain unexplained must find it incredibly frustrating not knowing exactly what happened. It is only in rare cases like that of Gareth Williams that they are brought under the media spotlight.

Off the Map: The case of Jayden Wray

Jayden Wray, who died on July 25, 2009

This week it was reported that the parents of Jayden Wray had been cleared by the High Court of all responsibility for the death of their son.

As a result we have decided to remove the case from the map as it can no longer be said to be a homicide. Although experts disagreed about the cause of death, it is now thought that Rickets was responsible for the injuries.

This is how the case appeared before it was deleted:

Four month-old Jayden Wray died after suffering serious head injuries and fractures to his arm, leg and hands.

He was taken to hospital on July 22, 2009, after falling ill at the family home on the Barnsbury Estate in Islington, north London.

The boy died three days later at Great Ormond Street hospital.

His mother Chana Al-Alas, 18, and father Rohan Wray, 20, were initially charged with grievous bodily harm and released on police bail.

Following further medical reports, on August 3, 2010, they were charged with murder and causing or allowing the death of a child.

They went on trial at the Old Bailey on November 1, 2011. The prosecution claimed that Jayden died of brain damage after being shaken by his parents. The boy also suffered from Rickets, a softening of bones caused by vitamin D deficiency.

On December 9, 2011, both parents were cleared of all charges on the direction of the judge Stephen Kramer QC. He said he had made his decision because the expert evidence about the cause of death was contradictory.

Judge Kramer added: ‘The evidence is that the parents were acting properly and gave no cause at all for concern over their care for Jayden.’

The London Homicide Manual

How do detectives investigate a murder? Books, TV programmes and documentaries give us some idea – even if their focus is on a single grizzled cop who solves a homicide single-handed. But what exactly is the ‘procedure’ when that call first comes in about a dead body?

As it happens the Metropolitan Police have what is called the ‘London Homicide Manual Specific Operating Procedure’, described as ‘the premier instruction document on the investigation of homicide and unexplained death.’

What does it contain? The answer is we don’t know. Last month the Met agreed to release the document following a request under the Freedom of Information Act – but only after the majority of it was redacted under Section 31(1)(a)(b) on the grounds it was not in the public interest.

In their response, the Met admitted there was an argument for full disclosure:

Better awareness of the MPS and its procedures may reduce crime or lead to more information from the public.

This information could be a useful deterrent to those with criminal intent, as the abilities and capabilities of the MPS who are charged with enforcing the law by preventing and detecting crime and protecting the communities we serve will be apparent.  There is also a public interest in the transparency of policing operations.

Disclosure could provide the public with an understanding that public funds are being used appropriately.

But the Met also saw powerful reasons for withholding information about how they investigate homicide:

Release would have the serious effect of compromising law enforcement tactics and would also hinder the prevention and detection of crime.
In addition the release of any information that is directly concerned with the investigation of crime would prejudice investigations and any possible future proceedings.
Disclosure would technically be releasing very sensitive operational information into the public domain, which would enable those with the time, capacity and inclination to use the information contained in this document to map strategies to counter the techniques used by the MPS to investigate homicides.
Additionally MPS resources and its ability to operate effectively and efficiently would be directly affected as this information can be manipulated by those with criminal intent to operate without fear of prejudice in those areas.

The Met do have a point – it isn’t a good idea to give criminals information that helps them to get away with murder. To make an analogy (perhaps inappropriately), no football manager would publish his tactics ahead of a match.

Whether or not entire chapters had to be redacted is hard to tell. All we have is the titles – Responsibility for Investigation, Initial Response, Specialist Crime Directorate Response, Policy Guidance and Good Practice, Record Keeping, Murder Review, Use of HOLMES [Home Office Large Major Enquiry System] within the Major Incident Room.

What remains is the introduction and the first chapter dealing with the relevant homicide legislation.

This level of redaction appears to contrast with the ‘Territorial Policing SOP: Minimum Standards for the Primary Investigation of Crime’, which has already been released under the Freedom of Information Act. (pdf available via What Do They Know)

Should the manual have been released in full or is that taking ‘Open Justice’ too far?

London Homicide Manual – Introduction


MPS policy for the Investigation of Homicide and unexplained death (pdf)

MPA Overview of the allocation of resources for homicide investigations (2006)