Targeting Escalation of Intimate Partner Violence: Evidence from 52,000 Offenders

Abstract

Research Question Does the severity or frequency of intimate partner violence or abuse reported to police increase over time, once a unique perpetrator-victim couple has come into contact with police in Thames Valley, UK? Data A total of 140,998 recent (non-historical) incidents of intimate partner violence or abuse reported to Thames Valley Police in 2010-2015 were identified, with 52,296 unique perpetrators for whom a standard 731-day observation period was possible after each perpetrator's first incident was reported in the intake period from 1 January 2010 through 31 December. Duplicate entries were eliminated and standard eligibility criteria were assured by data cleaning from the NICHE records management system of Thames Valley Police. Methods All non-crime incidents or reports of crime against intimate partners were coded by the Cambridge Crime Harm Index (CHI) with the sum of total days of recommended imprisonment for each offence (as the guideline starting point for sentencing) summed across all offences for each offender (Sherman et al. in Policing, 10(3), 171-183, 2016), with CHI scores for each successive incident plotted in sequence. Prevalence and frequency of repeat police contacts were also computed for each perpetrator, as well as the conditional probability of each new offence given the number of prior offences. Findings Most perpetrators identified in the 52,296 initial reports (77.6%) had no report of crime after the initial report. A further 21.2% had crime harm totals of less than 10 days of recommended prison time, with only 893 (1.7%) of the total universe of 4 years' worth of perpetrators who had a reported crime harm total over offences with a DOI 10.1007/s41887-017-0008-9 recommendation of over 10 days sentencing in the 731-day observation period. A slightly larger 'power few' of 3% of perpetrators accounted for 90% of total intimate partner abuse crime harm inflicted by all perpetrators, while 97% of perpetrators produced only 10% of total crime harm. Overall, amongst the few who had numerous repeat incidents, there was increasing frequency but no evidence of increasing seriousness of harm caused to victims. The 100 most harmful offenders in 2010 maintained a high (but greatly decreased) level of harm in 2011, but on average were very low harm offenders in [2012][2013][2014][2015].Conclusions This analysis suggests that the intimate partner abuser population is highly segmented in Thames Valley, with a small power few inflicting most of the harm. While the most serious offenders may remain difficult to identify prospectively, any valid prediction model could help to prevent a substantial amount of crime harm against intimate partners. Investing in such prediction methods may do more to help victims than an undifferentiated strategy putting most resources into low-risk cases.

Targeting the Most Harmful Offenders for an English Police Agency: Continuity and Change of Membership in the “Felonious Few”

“…It has, for example, examined overall offending in domestic abuse for any evidence of escalation in severity of harm inflicted against victims. Neither Bland and Ariel (2015) nor Barnham et al (2017) found any pattern of escalation in harm of domestic crime among abusers repeatedly reported to police. Where there is evidence of re-offending from these cohorts, average crime harm scores did not exceed the first-year average crime harm score; in fact, these power few offenders, as the studies described them, showed de-escalation in the severity of their offending.…”

“…Yet whether the concentration being described is measured by offending volume or by the sum of its severity can make a big difference in the meaning of the concept. The total volume of an individual's crimes, as recent evidence shows (Barnham et al 2017;Bland and Ariel 2015), is not a good predictor of the total harm from an individual's crimes.…”

“…Where there is evidence of re-offending from these cohorts, average crime harm scores did not exceed the first-year average crime harm score; in fact, these power few offenders, as the studies described them, showed de-escalation in the severity of their offending. Bland and Ariel (2015) and Barnham et al (2017) both also explored intermittency and conditional probability of further frequency of events; they both found support for increasing probability of a further offence with each additional crime and decreasing intermittency between each passing event. Both also found high levels of concentration in harm levels among a proportionally small group of person-based units (dyads for Bland and Ariel, and offenders for Barnham et al).…”

Targeting the Most Harmful Co-Offenders in Denmark: a Social Network Analysis Approach

“…As pointed out by Norton et al (2018), a crime hotspot with 30 robberies in a given year is not the same as one with 30 thefts: the severity of these behaviours is not the same. In domestic violence studies, a very small subset of offenders has been found to cause the most harm to victims (Barnham, Barnes, & Sherman, 2017;Bland and Ariel 2015). Dudfield et al (2017) have shown that fewer than 5% of victims suffer 85% of the harm, with sex offences and robbery contributing almost two-thirds of total harm (63%).…”

Integrated case management of repeated intimate partner violence: a randomized, controlled trial

“…One reason may be that most IPV cases have no repetition reported to police (Bland and Ariel 2015;Barnham et al 2017). Because the likelihood of further violence reported to police increases with the number of priors, it seems likely that a programme targeted on dyads with repeated reports to police might have a greater chance of showing a measurable effect.…”