Average rape sentences: Peer's question reveals more data

During the controversial Ken Clarke interview on Radio 5 Live last month, BBC presenter Victoria Derbyshire claimed that the average prison sentence for a rape conviction was five years. A subsequent Full Fact investigation found that Ms Derbyshire was mistaken, with the actual figure being closer to eight years on average.

However few details were available from the Ministry of Justice about how representative this figure really was, so Full Fact asked Baroness Stern to table a Parliamentary Question. This PQ has now been answered, and the results are shown in the graph below:

The numbers show that the eight year average is more or less accurate, though a number of cases with indeterminate sentences may skew the results depending on the decisions of the Parole Boards overseeing these cases.

There were 885 immediate custody rape cases that lead to determinate sentences in 2009 and 2010. Of these, 18.9 per cent of rapists were sentenced to fewer than five years, while nearly half serve five to 10 years. The remaining third serve sentences of 10 years to life.

An important caveat, however, is that these numbers do not take into account 315 cases resulting in indeterminate sentences for public protection. These cases constitute 17.5 per cent of immediate custody cases, a large enough proportion to have a significant impact on the eight year average. Offenders given indeterminate sentences can be kept in custody until they are judged to no longer pose a threat to society.

At this time, Full Fact doesn't have sufficient information to determine the average length of time rapists receiving an indeterminate sentence serve. In 2009, the minimum time spent in prison for these cases — known as the "tariff" period — was 5.1 years, though the actual time spent in custody is longer. As quoted in the 19 May factcheck, a Minister of Justice spokesperson has said that these indeterminate sentences "are likely to be some of the most serious cases which would otherwise have received a long determinate sentence."

The lack of information concerning the length served by indeterminate sentences means that the eight year average may not tell the entire story. If these indeterminate cases were included when calculating the 'average' rape sentence, there is a good chance that it would be notably higher than eight years.