2. Trends in conviction rates
( Tables 4a-c)
Conviction rates are calculated by dividing the number of people convicted by the number of people proceeded against. Eighty six per cent of people proceeded against in court in 2016-17 were convicted after being found guilty of at least one charge (92,334 people). This is the same proportion as in 2015-16 but four percentage points less than in 2007-08 when 90% of people were convicted.
Conviction rates are highest for motor vehicle offences, with 93% of people proceeded against being convicted in 2016-17. In particular, speeding offences had a conviction rate of 98% whilst the lowest rate was for rape and attempted rape (39%). Further detail for acquittals can be seen in section 3 with respect to rape and attempted rape.
Over the last ten years the largest declines in conviction rates have been for:
- Robbery, down 11 percentage points from 82% in 2007-08 to 71% in 2016-17; and
- Sexual assault, down 11 percentage points from 71% in 2007-08 to 60% in 2016-17. The number of proceedings for these types of crimes has doubled in this period, from 204 proceedings 2007-08 to 442 in 2016-17.
- It should also be noted that conviction rates for miscellaneous offences relating to urinating etc have fallen by 22% since 2007/08, but the total number of proceedings for such offences has fallen by 97%.