Has the murder rate doubled since hanging was abolished?

Since the Government launched its e-petitions website earlier this month, promising to consider petitions garnering over 100,000 signatures for debate in the Commons, one issue has dominated the early running: the reintroduction of the death penalty.

Full Fact previously looked at the claim that countries with capital punishment actually suffered from higher homicide rates, and as competition for signatures hots up, the campaign group Restore Justice has argued in a series of internet banners that since hanging was abolished in 1964, the UK "murder rate has doubled."

Is this really the case?

The Home Office hasn't actually recorded a 'murder rate' for several decades, as since 1972 the crimes of murder, manslaughter and infanticide have been compiled to make a homicide rate. (This was done because a large number of such cases are switched between the three categories in response to evidence and other changes of circumstances, meaning that the number considered 'murder' can change depending upon the point in criminal proceedings at which it is measured.)

However if we consider changes to the homicide rate since the abolition of the death penalty in this country, then we can begin to put these claims into context.

Using the Home Office's recorded crime statistics and population estimates from the Office for National Statistics, we can see that the homicide rate in 2009/10 was 11.2, compared to 6.3 in 1964, close to a doubling, if somewhat short.

But a look at the time series data might suggest that at its peak in 2002, the homicide rate reached three times that of the mid-Sixties. So has the Restore Justice campaign underplayed the rise?

Here, appearences can be deceptive. In 1998 the Home Office made a change to the way in which homicide was recorded by police, which had a significant impact upon the results produced.

Whereas before 1998 multiple murders were considered as a single incident, afterwards each death was considered seperately. In 2002, the figures included the 173 murders committed by Harold Shipman, whereas if these had been committed in 1964, they would have only counted as one incident for the purposes of the Home Office statistics.

Of course this could also mean that the difference between the most recent year from which there is data and 1964 might also be exaggerated. To do a true like-for-like compaison therefore we would need to limit the analysis to the years 1964-1997.

However even within this timeframe it would appear that the homicide rate did indeed double. In 1997 the homicide rate stood at 14.1, still more than twice the 1964 level.

But there are some factors that need to be considered here.

In particular, it is worth noting that the homicide rate itself is not a static figure, and is frequently revised in response to developments in cases. The reported homicide rate totals the number of incidents initially treated as murder, manslaughter or infanticide by police when they begin investigations. However this can fall in subsequent months and years in response to new information (for example, as cases initially considered murder are revised to suicide).

If we look specifically at cases still considered homicide at the end of the period (as the House of Commons Library did in 1999), then the change in the murder rate between 1967 (the earliest year for which data is available) and 1997 is more modest. In 1967 this rate stood at 7.3, and reached a peak of 12.8 in 1995, falling slightly to 12.4 in 1997. In this analysis therefore, the homicide rate did not quite double.

The claim that the 'murder rate' has doubled since hanging was banned can therefore be backed up, given the right caveats. As with any complex subject however, there are a number of different ways in which the data can be interpreted, and whether or not the homicide rate quite doubled, it does not necessarily follow that there is a direct causal link between this and the abolition of capital punishment.