Implementing a Crime Harm Index in Western Australia

Mr Paul House1

1Wa Police, Perth, Australia

Counts of reported crimes, arrests and response times have long been the yardsticks by which police performance has been measured. Western Australia Police rely on internally reported crime statistics for performance grading and resource allocation within the force. Yet that methodology provides little guidance for consideration of the large differences in harm that societies attribute to various crime types. For example, some crimes cause severe injuries or death and others cause scant harm, but for the most part they are counted equally.

This paper seeks to address that inequality, by answering the research question: Can a reliable measure of precise harm levels for the 100 most harmful and frequently occurring offences be developed in Western Australia (WA) based on analysis of actual court penalties for first-time offenders? Criminal and traffic court sentences in 2.2 million records over 7 years were analysed to extract the number of days of imprisonment actually imposed in sentencing decisions for approximately 52,000 first-time offenders. Monetary penalties and conditional community sentences for those offenders were converted to equivalent ‘prison days’ and added to the computation of the median of days of imprisonment per offence category. This process was successful for 88 of the 100 offence categories, each then assigned a weighted harm index value. A sample of WA Crime Harm Index (WACHI) values correlated strongly with other international harm indices, validating the calculation method.

Since the research was completed, harm values have been imputed for 1300 offence categories and applied to measure harm trends and the effectiveness of police practises in Western Australia.


Paul House is the Data Analytics and Assessment Manager within the WA Police Office of Applied Criminology (OAC). He has worked in the unit since its inauguration in 2015 and manages a team of analysts, interns and graduates who conduct analysis for their evidence-based experiments. He recently completed a Master of Studies degree in Applied Criminology and Police Management at Cambridge University, United Kingdom.

Prior to working in OAC, Paul worked for two years as a senior intelligence analyst. This involved an intelligence coordination role where he directed the analytical support for the Metropolitan Region and for the Serious and Organised Crime Division; drawing from his previous experience working in Canberra for the Department of Defence as an imagery and geospatial analyst.

Paul holds a Bachelor of Science degree from Edith Cowan University in Western Australia, majoring in Aviation, with minor studies in physics and chemistry. Prior to his career in intelligence, Paul worked in the aviation sector for eight years as a flying instructor in Perth and for a short period in China. He holds a grade one Flight Instructor rating and an Airline Transport Pilots Licence.

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