The Violence Reduction Strategy (VRS), an initiative of the Chicago Police Department (CPD), is designed to lessen the impact of violent crime on our community. An important component of the VRS is the Custom Notifications program, which is a partnership between CPD and the John Jay College of Criminal Justice. As part of this initiative, John Jay’s Community team coordinates outreach to help individuals who are at especially high risk for involvement in violence to find a better path forwards for themselves and their families with the involvement of social service and community partners.

To prioritize the program’s outreach efforts, CPD reviews many sources of information to determine which individuals may be at greatest risk. Among these considerations is a review of information related to an individual’s participation in a VRS “call-in,” a meeting in which a group of persons known to be involved with street gangs having ongoing violent conflicts are brought together with police, community representatives, and social services personnel, with the aim of urging the at-risk persons to stop the violence. Individuals may also be identified as being at risk based on District Gang Audits, human intelligence, information about the individual’s criminal activity, and conflicts within the district.

Custom Notifications Program

In the Custom Notifications program, an at-risk individual or family of that individual is contacted, including an in-person visit. Those visiting with the individual, which include representatives of CPD and the Custom Notifications program, appeal to the individual to steer away from activities that put them at sustained risk for involvement in violence. In addition, the program attempts to engage the help of friends and family of at-risk individuals to influence them in a positive direction. During a Custom Notifications visit, the at-risk individual is reminded of the serious risks and consequences of his or her current involvement in crime. A key part of the solution that is offered is to connect the individual to social services that can assist the individual in this process. A person is only considered to be at risk by the program due the specific nature of his or her specific recent involvement in crime, not generic factors relating to personal attributes or the overall presence of crime in the community.

Per Chicago Police Department Special Order #S10-05 factors for eligibility to receive a Custom Notification Letter include, but are not limited to severity of risk according to the Crime and Victimization Risk Model; Being the victim of a shooting incident, where prosecution has been declined for lack of cooperation; Identification as a repeat offender for public violence crimes; Other factors as developed and linked to public violence within the district.

To prioritize the program’s outreach efforts, CPD reviews many sources of information to determine which individuals may be at greatest risk. Among these considerations is a review of information related to an individual’s participation in a VRS “call-in,” a meeting in which a group of persons known to be involved with street gangs having ongoing violent conflicts are brought together with police, community representatives, and social services personnel, with the aim of urging the at-risk persons to stop the violence. Individuals may also be identified as being at risk based on District Gang Audits, human intelligence, information about the individual’s criminal activity, and conflicts within the district.

More information about the Custom Notifications program can be found at John Jay’s website here: https://nnscommunities.org/our-work/innovation/custom-notifications

Crime and Victimization Risk Model

A further source of information that is considered in the deliberation on prioritization is a statistical risk model that follows an approach similar to that used in the public health arena. This statistical tool, known as the Crime and Victimization Risk Model (CRVM), was developed at the Illinois Institute of Technology under an academic research grant sponsored by the National Institute of Justice, which is a branch of the U.S. Department of Justice. The CVRM is only used as an informational tool, along with the other pieces of data described above, to help to prioritize the Custom Notifications process. Under no circumstance does this statistical model enter into enforcement decisions of any kind (such as arrests), and the risk estimates provided by the statistical model never trigger any automatic actions of any kind. At-risk individuals are identified by experts based on a holistic view of available information that is indicative of risk.

In the fields of public health and preventive medicine, it is common to use statistical models to identify health risks (such as cancer) and the factors that contribute to these risks (such as smoking). In a similar fashion, theCrime and Victimization Risk Model (CVRM) is a statisticalmodel that estimates an individual’s risk for becoming a victim or arrestee in a shooting or homicide in the next 18 months based on risk factors in a person’s recent crime record. For example, a person’s risk of being shot is increased by the fact that he has been shot recently on multiple occasions.

The risk estimates produced by the CVRM are based entirely on recent crime incidents in which an individual was a victim or arrestee, and the CVRM never considers personal attributes such as race, gender, ethnicity, or place of residence. In fact, beyond the victimization and arrest data, no other information of any kind is used to form the risk estimates.

The CVRM is analogous to a web search in that both serve as informational tools designed to help identify potentially relevant information from among a very large set of data that would be impossible to sift through manually. Thus, the CVRM is applied to CPD’s crime records from the past four years, the goal being to identify patterns of crime activity that may indicate risk, so that experts can review the underlying details, along with the various other sources of information described earlier, in prioritizing the Custom Notifications process.

Below is a table of the risk estimates for those persons in Chicago who have been arrested in the past four years. Risk estimates are computed for these individuals for the sole purpose of finding just the small group that may be at highest risk, so that the details of their crime records can be studied by experts for purposes of prioritizing the Custom Notifications program.

Download CVRM Fact Sheet


The current version of the CVRM estimates risk according to a system of “tiers.” Based on historical data, the chance of being involved as a victim or arrestee for individuals in the various tiers is given in the table below.

Tier Risk Level Risk (Probability)
1 Very High 27-35%
2 High 15-27%
3 Moderate 5-15%
4 Low 1-5%
5 Very Low 0-1%

Explanation of Data

Individuals are sorted by IR number, and the columns in the spreadsheet are organized as follows:

1. IR number
2. Risk tier: 1 (very high), 2 (high), 3 (moderate), 4 (low), 5 (very low)
3. Number of times first-degree co-arrestees were prior PTV
4. Number of times second-degree co-arrestees were prior PTV
5-10. The subject’s 6 attributes (see below for description)
11-16. Breakdown of risk assessment into % contributions from the 6 attributes (this is the information necessary to create the Attribute weight graph)
17-22. “Severity” scores for the 6 attributes (this is the information necessary to create the Attribute severity graph)

The 6 attributes (by order of importance) are:

  1. Victim of shooting incident
  2. Age during the latest arrest
  3. Victim of aggravated battery or assault
  4. Trend in criminal activity
  5. UUW arrests
  6. Arrests for violent offenses

Note that the victims and arrest attributes shown in the table are simple counts of crime incidents. The CVRM actually weights each incident according to the time that has elapsed since it occurred.