“The conviction rate for rape and sexual offences fell between 2008 and 2013”

That’s what justice secretary Dominic Raab told BBC Radio 4 on Tuesday.

He’s talking about the period when now-Labour leader Keir Starmer was head of the Crown Prosecution Service (CPS) for England and Wales.

But there’s more to this claim than meets the eye.

Conflicting figures

Mr Raab’s claim was based on his department’s figures, which show rape conviction rates fell from 38.5 per cent in 2008 to 33.8 per cent in 2013.

For other sexual offences, the gap was greater: using government data, we calculate a decline from 68.8 per cent to 59.5 per cent.

But statistics from the CPS tell the opposite story.

They chart a rise in rape conviction rates from 57.7 per cent to 60.3 per cent, and from 75.1 per cent to 79 per cent for other sexual offences.

What’s going on?

The MoJ and the CPS use different techniques to calculate their conviction ratios.

CPS figures run between financial years (April to April), while the MoJ uses calendar years (January to January).

The MoJ compares the number of offenders convicted in a given year with the number of defendants prosecuted in the same year.

Conversely, the CPS tracks cases through the courts, showing us convictions and prosecutions relating to the same case in a given year’s stats.

The bigger picture

When we’re talking about rape conviction rates, we should remember that the vast majority of offences are never brought to court.

In 2020-21, just 1.5 per cent of all rapes that were recorded by the police resulted in a charge, according to MoJ statistics.

That’s down from 8.5 per cent in 2014-15, when comparable figures first began.

FactCheck verdict

Dominic Raab said that the conviction rate for rape and sexual offences fell between 2008 and 2013, when Keir Starmer was director of public prosecutions in England and Wales.

This is consistent with figures from the Ministry of Justice. But separate data from the Crown Prosecution Service shows the opposite trend, with conviction rates rising over Mr Starmer’s tenure.

The mismatch is the result of different measuring techniques in the two organisations.

We should also bear in mind that conviction rates only tell us about the cases that make it to court, which are a tiny fraction of all rapes reported to the police.