Did crime fall while Boris Johnson was Mayor of London?

“We got crime down by 20% [in London]. We got the murder rate down.”

Boris Johnson MP, 3 June 2019

In his campaign launch video, Conservative party leadership candidate Boris Johnson said that, as London mayor, he got crime down by 20% and the murder rate fell.

It’s correct the homicide rate fell. We don’t know exactly how Mr Johnson calculated the drop in overall crime, but 20% is a fair estimate, although this figure only includes crimes recorded by the police.

The homicide rate

The homicide rate recorded by the Met Police halved between 2007 and 2014, during Mr Johnson’s time as mayor, before increasing slightly towards the end of his tenure.

Homicide figures are often used to describe the number of murders or the murder rate, but these figures include manslaughter and infanticide charges as well as murders. The available figures do not record murder, manslaughter and infanticide separately.

We’ve asked Mr Johnson’s office for the source of these claims, and have factchecked similar claims from him before. We’ve assumed he was using the term “murder” and “homicide” interchangeably. 

In the year before Mr Johnson became mayor (2007/08), there were 163 homicides recorded by the Met, or roughly 21 per million, using population estimates for the time. In 2014 the rate had reduced to 12 per million, down by about half, though this had ticked up slightly to 13 per million in the year from April 2015 to March 2016, Mr Johnson’s last year in office.

The crime level

We’ve asked Mr Johnson how he calculated crime had fallen by 20% while he was mayor. But we think his claim is broadly accurate, using the best available data.

In measuring the total crime level in England and Wales, there are two main sources available—police recorded crime, and the crime survey. 

They each have strengths and weaknesses, which we cover in more detail here, but broadly speaking, it’s best to use crime survey data to measure a total crime level. Unfortunately, you can’t see from the publicly available data where a crime took place so we can’t look at crime in London using the survey data.

So that leaves us with police recorded crime.

In 2007/08, the year before Mr Johnson became mayor, there were around 850,000 recorded crimes in London, or 110 per 1,000 residents.

In his final year as mayor, this had decreased to about 740,000 or 85 per 1,000 residents, a drop of 23% over the period.

These figures refer to crimes recorded by the Metropolitan Police. They exclude most fraud offences as, during this time, responsibility for recording fraud offences in London passed from the Metropolitan Police to the national fraud reporting service Action Fraud, and so, according to the ONS, “it is not possible to make meaningful year-on-year comparisons over this period.”

Trends in London need to be seen against the context of what’s happening across England and Wales as well. Over the same period, crime (including fraud) also fell across the country, but at a slower rate – about 14% between 2007/08 and 2015/16.

There are various other caveats with this data. Police figures are only as good as the police’s own recording practices, which haven’t been consistent in quality over time, and can also be impacted by changing policing priorities.

These figures also don’t record crime that isn’t reported to the police.

Changes in the population can also affect the number of crimes happening, so what we’ve done here to calculate the crime rate is look at how many crimes were reported per 1,000 London residents. But of course at any given point there are likely more people in London than live there (whether they be tourists or commuting workers) so it won’t be a perfect measure.