Criminal justice outcomes for cannabis use offences in New Zealand, 1991-2008.

BACKGROUND: There have been no changes to the statutory penalties for cannabis use in New Zealand for over 35 years and this has attracted some criticism. However, statutory penalties often provide a poor picture of the actual criminal justice outcomes for minor drug offending.

AIM: To examine criminal justice outcomes for cannabis use offences in New Zealand over the past two decades.

METHOD: Rates of apprehension, prosecution, conviction and related criminal justice outcomes for the use of cannabis in New Zealand (per 100,000 population) were calculated for 1991-2008. The same measures were calculated (per 1000 last year cannabis users) for 1998, 2001, 2003 and 2006. Trends were tested for using logistic regression with year predicting each measure outcome and with chi-square tests.

RESULTS: The number of police apprehensions for cannabis use per year (per 100,000 population) declined from 468 in 1994 to 247 in 2008. The number of apprehensions for cannabis use per year (per 1000 cannabis users) also declined from 36 in 1998 to 21 in 2006. There were similar declines in prosecutions and convictions for cannabis use from 1991 to 2008. Those prosecuted for cannabis use in 2000-2008 were less likely than those prosecuted in 1991-1999 to be convicted and were more likely to be diverted away from the courts, 'discharged without conviction' and 'convicted and discharged'.

CONCLUSION: There has been a substantial decline in arrests for cannabis use in New Zealand over the past decade and this lead to similar declines in prosecutions and convictions for cannabis use. The decline in convictions for cannabis use was further assisted by the expansion of police diversion to include cannabis use offences. Our findings underline the importance of examining the implementation of law, as well as statutory penalties, when characterising a country's criminal justice approach to minor drug offending.