Predicting high harm family violence offenders using the WA Crime Harm Index

Mr Paul House, Data Analytics Manager, WA Police.

At every domestic violence scene, Police officers collect information that helps them to understand the nature of the crime and antecedents of a victim-offender relationship. Sometimes this information is used reactively to prioritise follow up actions by community services, or by Police to inform a court case. More often than not however, it is stored in a Police database waiting for a researcher to describe the bigger picture.

Increasingly, these data are used to predict future offending by incorporating the demographic, modus operandi and offender specific attributes in a predictive analytical model. Predictive models can tell us how likely an offender is to reoffend or even how many times they will reoffend. But identifying their future impact on the community is more complex than simply counting up the number of prior offences. So how can we use data collected by Police to give us the best chance of targeting community harm?

In this presentation you will see how a crime harm index can be used in a simple predictive model. Demographic and criminal history characteristics for a cohort of 14,277 family violence offenders were assessed, with reoffending analysed over a two year follow up period. A logistic regression model was employed to determine the common characteristics for those who committed subsequent high harm offences. The model was bolstered by data from the WA-specific Family Violence 1-9 risk identification tool and reoffending was assessed against a harm threshold, drawn from the recently developed WA Crime Harm Index.


Biography:

Paul House is the Data Analytics and Assessment Manager within the WA Police Operational Standards Unit. He worked in the Evidence Based Policing Unit from its inauguration in 2015 through to 2018. Paul currently manages a team of analysts and interns who support external researchers and inform the evaluation of operational standards. In 2017 he completed the Master of Studies degree in Applied Criminology and Police Management. Paul has also worked in the Defence Intelligence and Aviation sectors.