A systematic review of the efficacy of specialist police investigative units in responding to child sexual abuse

Dr Nina Westera, Dr Elli Darwinkel and Dr Martine Powell

March 2016

ISBN 978-1-925289-45-9

Executive Summary

Aim of the review

Aim of the review Investigating allegations of sexual abuse against children is a highly complex task that requires a specialist response from police. One way policing organisations have responded to this need is to establish specialist investigative units, where a team of police officers are co-located, sometimes with other agencies, to perform the primary role of investigating sexual abuse cases. Given the influx of these units, it is prudent to critically evaluate their efficacy to determine whether this is the best and most cost-effective response for victims of child sexual abuse. To date, no one has conducted a systematic and holistic review of the efficacy of this system.

This report was commissioned by Australia’s Royal Commission into Institutional Responses to Child Sexual Abuse, to provide a comprehensive, systematic review of the international literature, critically evaluating:

  • what is known about the efficacy of specialist police investigative units compared to traditional responses
  • what features of specialist units might determine their effectiveness. 

Key findings

Overall, 23 out of 27 evaluations of the specialist investigative units found that these units resulted in a more effective police response than traditional approaches. This improvement was reflected in the four main categories measured in these evaluations: victim satisfaction, professional stakeholder satisfaction, investigative process and investigation outcomes. Special units either improved outcomes in these measures or left them unchanged (that is, they did not have negative consequences).

Inadequacies in the design of these evaluations made it difficult to draw clear conclusions about the efficacy of specialist units. The direct comparison studies only related to four of the 11 different specialist units, all of which were multi-agency centres. This small number makes it impossible to delineate which features of the specialist units make them more or less effective. The features of each unit and the measures of each evaluation varied: some involved multi-agency responses whileothers involved a police-only specialist response; there were different levels of training, types of co-location, and referral processes.

Victim satisfaction
Qualitative surveys and interviews with adult victims and the families of child victims suggest that these participants were more satisfied with a specialist unit than a traditional response. Studies examining child satisfaction are too few to draw any conclusions about this group. The specialist units recorded higher victim participation levels compared to traditional responses, but findings as to how this affected reporting rates to police were unclear. Positive results from specialist unit involvement included the victim feeling valued by police, having greater privacy and having improved access to services. However, some victims were still concerned about negative police attitudes and lengthy delays in investigations.

Professional stakeholder satisfaction 
Qualitative surveys and interviews suggest that professional stakeholders strongly support specialist units as opposed to a more traditional response. Professional stakeholders mostly cited improved response effectiveness and increased job satisfaction as the main benefits. They supported the need to co-locate agencies and a deliver service by way of a collaborative approach between agencies.

Investigative process 
Cases involving specialist units reported higher rates of police, Child Protective Services (CPS) and medical service involvement compared to cases dealt with via traditional responses. The extent of delays in investigation times did not change, but professional stakeholders suggested that specialist unit involvement improved the timeliness and ease with which victims were able to access services. There is insufficient research to conclusively determine the influence of specialist units on the quality of investigation.

Investigation outcomes 
Specialist units recorded higher arrest rates and numbers of charges compared to traditional responses. However, there was not enough evidence to draw any conclusions about how specialist units influence prosecution and conviction rates, or sentence length.