By Steve Yeong

Background

The Suspect Target Management Plan (STMP) is a New South Wales Police Force initiative designed to reduce crime among high risk individuals through proactive policing. There are two types of STMP: STMP-II, which was introduced in May 2005 and aims to reduce general offending; and DV-STMP, which was introduced in October 2015 and aims to reduce domestic violence related offending.
The objective of the present study is to determine: (1) whether these programs reduce crime; (2) how these programs reduce crime (i.e., through deterrence or incapacitation); (3) to determine whether (1) and (2) differ for juveniles or Aboriginal people.

Key findings

This study compared the outcomes of individuals in the 12 months before and after placement on STMP-II (n=10,106) and DV-STMP (n=1,028). The investigation of STMP-II focuses on a subset of violent and property crimes to avoid reporting/detection bias. The investigation of DV-STMP focuses on domestic violence related crimes since they are the focus of the program. These crimes are, however, likely to be influenced by reporting bias. Due to methodological constraints, caution is recommended when interpreting the non-causal, associative estimates reported in this bulletin.

The findings can be summarised as follows:

STMP-II is associated with large, practically and statistically significant reductions in property crime.DV-STMP is associated with large, practically and statistically significant reductions in domestic violence related crime.Although STMP-II is associated with an increased risk of imprisonment, the association between STMP-II and crime is likely driven by deterrence, not incapacitation.DV-STMP is not associated with an increased risk of imprisonment.The reduction in crime associated with STMP-II for juveniles is larger than it is for adults.The increase in the risk of a prison sentence associated with STMP-II is smaller for juveniles relative to adults.The reduction in crime associated with STMP-II for Aboriginal people is smaller than it is for non-Aboriginal people.The increase in the risk of a prison sentence associated with STMP-II is larger for Aboriginal people relative to non-Aboriginal people. Although STMP-II is associated with an increased risk of a prison sentence for juveniles and Aboriginal people, the association between STMP-II and crime is likely driven by deterrence.

Conclusion

Both STMP-II and DV-STMP are associated with a reduction in crime. The findings suggest that any crime reduction benefit for both programs is likely due to deterrence rather than incapacitation. These claims are also true for juveniles and Aboriginal Australians.

(Crime and Justice Bulletin No. 233 revised). Sydney: NSW Bureau of Crime Statistics and Research. 2021. 33p.