13.5 Major Offence
The method of choosing the major offence and thus categorising offenders has changed over the years. The method used by the Department (and later, Ministry) of Justice from 1987 to 1997 was based on a hierarchy of selection criteria until one type of offence remained for each inmate. Firstly, offences with the longest sentence imposed were selected, then those with the largest seriousness score, then those with the smallest offence code (as the more serious offences have the smallest offence code numbers).
The following history of the major offence definition is given in a Department of Justice publication.
“A seriousness of offence scale was originally developed by the Policy and Research Division of the Department of Justice in 1991 (see Spier, Luketina, & Kettles (1991)). The most recent update of the scale occurred in 2000 by the Ministry of Justice. The updated scale gives imprisonable offences a score according to how serious judges have deemed each offence in terms of the use of custodial sentences over a specific time period. These scores enable offences to be ranked in terms of their relative seriousness, and can be used to examine whether offending that leads to conviction has become more serious over time (i.e. whether there has been an increase in the number of more serious offences relative to less serious offences over time).
"The updated scale is based on court sentencing data for the period 1995 to 1999. The seriousness score assigned to each offence is the average number of days of imprisonment imposed on every offender convicted of that offence between 1995 and 1999, where the average is taken over both imprisoned and non-imprisoned offenders. Suppose, for example, that between 1995 and 1999 there were 100 cases of offenders convicted of a particular offence. Of these cases, 50 resulted in a custodial sentence, and the average length of the custodial sentences imposed on these offenders was 30 days. The seriousness score for this offence is (30 x 50/100), or 15.
"Offences that became obsolete prior to 1995 were given the same score as any new similar offences, or a score was calculated based on sentencing data before 1995. Imprisonable offences for which there were convictions but no custodial sentences over the period 1995 to 1999, were given a seriousness rating slightly lower than the least of the offences already assigned a seriousness score (i.e. a score of 0.2). Non-imprisonable offences were assigned a seriousness score of zero.”(1)
Despite the changing methods of categorisation, little change is evident in the composition of prison population over the past decade. Violent offenders continue to constitute the largest category of sentenced inmates, especially for males.
Table 13-8 Major offence of sentenced females (percent)
|
Major offence |
1991 |
1993 |
1995 |
1997 |
1999 |
2001 |
2003 |
|
|
% |
% |
% |
% |
% |
% |
% |
|
Violence / sex |
31.3 |
45.3 |
37.1 |
34.3 |
40.2 |
46.4 |
39.3 |
|
Property |
44.3 |
33.3 |
39.7 |
41.1 |
29.9 |
27.3 |
31.7 |
|
Drug |
16.0 |
13.7 |
12.6 |
12.0 |
15.2 |
12.9 |
17.6 |
|
Traffic |
7.6 |
2.6 |
7.3 |
6.8 |
10.8 |
9.3 |
8.4 |
|
Other |
0.8 |
5.2 |
3.3 |
3.9 |
3.9 |
4.1 |
3.1 |
|
Total |
100.0 |
100.0 |
100.0 |
100.0 |
100.0 |
100.0 |
100.0 |
Table 13-9 Major offence of sentenced males (percent)
|
Major offence |
1991 |
1993 |
1995 |
1997 |
1999 |
2001 |
2003 |
|
|
% |
% |
% |
% |
% |
% |
% |
|
Violence / sex |
53.8 |
63.2 |
62.4 |
58.8 |
61.9 |
61.8 |
59.1 |
|
Property |
25.4 |
20.6 |
21.3 |
21.7 |
21.2 |
21.6 |
21.7 |
|
Drug |
7.3 |
6.0 |
5.8 |
7.0 |
7.5 |
7.8 |
8.3 |
|
Traffic |
10.1 |
8.5 |
8.9 |
10.0 |
7.2 |
5.7 |
8.2 |
|
Miscellaneous |
3.5 |
1.7 |
1.7 |
2.5 |
2.2 |
3.0 |
2.7 |
|
Total |
100.0 |
100.0 |
100.0 |
100.0 |
100.0 |
100.0 |
100.0 |
1 Spier, P., Luketina, F., & Kettles, S. (1991) Changes in the Seriousness of Offending and in the Pattern of Sentencing: 1979 to 1988, Department of Justice, Wellington.