The police-reported Crime Severity Index (CSI) is a summary measure of the volume and severity of police-reported crime in an area—a city, a province or territory, or the country.
However, the CSI is not intended to be used in isolation and is not a universal indicator of community safety. This paper highlights the origins of the CSI and the importance of interpreting the Index in conjunction with other data sources to better understand crime in a given area.
More detailed methodology and reference publications are also highlighted at the end of this paper.
The origins of the Crime Severity Index
Since the 1960s, police-reported crime from the Uniform Crime Reporting Survey (UCR)Footnote 1 has been understood through the conventional crime rate.
The Crime Severity Index (CSI) was developed in 2009 as a complementary measure to the conventional crime rate and self-reported victimization data.Footnote 2 It represented the first major change in how Statistics Canada looked at police-reported information in nearly 50 years.
The CSI is intended to be one of many sources of information that can be used to better understand the evolving nature of crime in Canada.
Combining information from different sources provides a more comprehensive understanding of complex issues. For example, there are many ways of looking at crime, including with police-reported crime counts, courts and corrections data, police resourcing data, as well as survey data on self-reported victimization and perceptions of safety and trust in institutions.
Each source offers a particular way to understand crime, and in combination with other indicators and information sources, society.
Measuring police-reported crime with the Crime Severity IndexFootnote 3
The conventional crime rate is calculated by adding up the number of crimes reported by police for a given period and geographical area and then dividing that total by the population count for the area. Therefore, each crime has the same impact on the crime rate—for example, one murder has the same impact as one theft.
Typically, more frequent but less serious crimes have the largest impact on the crime rate.
While this is a useful measure of the volume of crime coming to the attention of police over time, and therefore adding to our understanding of police workloads and demands on the justice system, it is not as effective at reflecting changes in less frequent but more serious crimes.
The CSI was developed to address the limitations of the conventional crime rate by looking at both the number and relative seriousness of crimes to create an index, and then tracks these changes over time.
In fact, there are three related indexes—the overall CSI, the Violent CSI and the Non-violent CSI—that look at different types of crime. A CSI is also calculated for youth accused of crime.
Measuring—or weighing—crime severity
To calculate the CSI, each type of crime is assigned a weight that represents its relative severity. Then, the number of police-reported incidents for a given type of crime is multiplied by the crime's weight. Assigned weights are based on standardized information from court sentencing data over the previous five years.Footnote 4
Crimes that are more likely to result in prison time and longer sentences are given a higher weight.
For example: Using the conventional crime rate, one property theft has the same impact on the crime rate as one murder. One incident of murder is therefore equivalent in weight to one incident of property theft.
However, in the Crime Severity Index, murder has a weight of over 8,200, while property theft has a weight of 29.Footnote 5 As such, the impact of one murder on the CSI is approximately 280 times greater than one property theft.
First-degree murder has a far heavier weight in the CSI than property theft, highlighting its severity, even though it happens far less frequently. So, relative to the conventional crime rate, the CSI will better reflect the impact of a change in the frequency of first-degree murder, whereas with the conventional crime rate, this change may go undetected.
Another way of looking at this is that the CSI is one way to more accurately reflect changes in instances of more serious but less frequent crimes in an area, while changes in less serious crimes will have less impact on the CSI than they do on the crime rate. This provides a more comprehensive and nuanced picture of crime, especially when combined with other measures of crime.
The CSI also allows for the comparison of changes in crime over time and across Canada when controlling for the unique circumstances of each area, such as how many people live in the area, the age and gender mix, employment opportunities and wages, level of remoteness and availability of services among others.
We can then interpret changes in the CSI within the context of other indicators.
Like any individual social, economic, or environmental indicator, other complementary sources of information, both within and outside the criminal justice system must also be considered Footnote 6 to draw a full picture of crime and safety in an area.
The Crime Severity Index was developed in conjunction with stakeholders and the public and is used to measure sustainable development goals
The CSI is a standardized and consistent measure of crime and a key indicator for the country. It uses standardized data from the UCR Survey, a census of all police-reported crime in Canada.
Extensive consultation and development work ensures the CSI is methodologically sound, easily understandable, and robust with respect to changes in crime.
The CSI is also an indicator in the Canadian Indicator Framework for reporting on the Sustainable Development Goals,Footnote 7 an international initiative to achieve a more sustainable and equitable future. It is also a key indicator in the Quality of Life Framework for Canada,Footnote 8 which brings together data on the well-being of Canadians.
As such, the CSI is one piece of a much larger puzzle that helps Canadians better understand the country—its population, resources, economy, environment, society and culture.
Key considerations when using the Crime Severity Index
At its core, the CSI is a measure of crime reported by police in a specific region. It accounts for the weighted severity of each reported crime, relative to the census population count in the area, expressed per 100,000 people.
Changes in population
Population counts used to calculate the CSI are derived from the once every five years Census of Population.Footnote 9 However, populations can be dynamic, especially in regions where the economy is largely driven by a seasonal activity such as tourism, or through certain business activity or border crossings.Footnote 10
Certain regions may also experience higher population movement or mobility due to several factors, such as the local job market, housing costs, location (city, town, remote area) and the presence or absence of community services in those areas.
These population characteristics must also be considered when interpreting crime trends.
Unreported crimes not covered by the CSI
The underlying data from the UCR Survey are a census of all crime coming to the attention of police in Canada.
The data go through rigorous quality assurance checks and are based on a standardized reporting manual for national crime statistics.Footnote 11
However, these data do not capture crimes that are not reported to police.
CSI updated regularly to reflect changes in legislation and sentencing
Data from the UCR Survey may also be impacted by more area-specific changes in police practices, police resources,Footnote 12 public awareness campaigns,Footnote 13 policing initiatives for tackling specific types of crime,Footnote 14 and the relationship between the public and the police.
The CSI weights are regularly updated to reflect changes in legislation and sentencing in Canadian courts.Footnote 15
Weights used to calculate the CSI are adjusted every five years, and the underlying methodology for counting crime is reviewed to ensure changes in legislation, crime reporting and court practices are considered.Footnote 16
Looking at the CSI through a diversity-focused lens
As an area-based measure, the CSI does not consider specific demographic characteristics of each area or how different groups of people in an area may experience harm and discrimination.
For example, First Nations people, Métis and Inuit are historically overrepresented among victims of homicide,Footnote 17 self-reported victims of violence,Footnote 18 and in the criminal justice system.Footnote 19Footnote 20 Colonialism, territorial dispossession, socioeconomic marginalization and systemic discrimination were identified as significant contributing factors to the overrepresentation of Indigenous people in the criminal justice system.Footnote 21
Sentencing provision for Indigenous people
The Canadian government, legislature and judiciary have sought to address the overrepresentation of Indigenous people in the Canadian justice system over time.Footnote 22 Specifically, paragraph 718.2(e) of the Criminal Code, introduced in 1996, sets out that before a court imposes a sentence, "all available sanctions, other than imprisonment, that are reasonable in the circumstances and consistent with the harm done to victims or to the community should be considered for all offenders, with particular attention to the circumstances of Aboriginal offenders."
This sentencing provision was first interpreted in the case of R v Gladue ("Gladue") in 1999. The Supreme Court decision in Gladue set out principles requiring that courts take the unique circumstances of Indigenous offenders into account in sentencing. The decision laid out a framework to help guide judges in sentencing Indigenous offenders. This led to the recommended use of "Gladue reports," which provide background information on an offender to assist in appropriate sentencing.
Various critiques and concerns about the application of Gladue were subsequently raised. In 2012, the Supreme Court in R v Ipeelee reaffirmed its commitment to the principles enunciated in Gladue, addressed a number of critiques and clarified concerns. The Supreme Court also recognized that the criminal justice system bore some of the responsibility for the offences discussed in the case.Footnote 23
Indigenous people also report lower levels of confidence in policeFootnote 24 and are more likely to report experiencing discrimination when dealing with the police than their non-Indigenous counterparts.Footnote 25
Calls to address systemic racism in policing and the relationship between police and Indigenous peoples have also been raised.Footnote 26
However, area-based measures of crime can potentially gloss over complex systemic issues in an area or between different groups of people, or they may reflect these underlying issues.
For example, the CSI does not account for particular socioeconomic context of an area or the the presence or absence of community services that may influence police responses in a given area.
It is therefore vital to consider additional context to better understand the lived experience of people in the area.
The foreword of Canada's Anti-Racism StrategyFootnote 27 acknowledges that the experiences of racism and discrimination among racialized communities and Indigenous peoples may vary. "Applying an intersectional lens reveals a complex picture of the way that different groups and individuals are excluded and harmed."
The strategy also states that "data and evidence are indispensable tools for identifying and addressing inequities, and enabling corrective action toward the elimination of racism and discrimination."
A major step in responding to increasing demands for better disaggregated data to shed light on people's diverse experiences with crime is Statistics Canada's Police-reported Indigenous and Racialized Identity Data Collection Initiative.Footnote 28Footnote 29
The importance of additional information and contextualization when using the CSI
Understanding crime in an area, and specifically the CSI, requires understanding which crimes are impacting the area and the factors influencing crime and reporting.
Every year, when police-reported information is published by Statistics Canada, a suite of data tables and analysis are accompanied by detailed footnotes and explanations to better understand changes in crime patterns. These are developed in part through discussions and follow-up with individual police services to better understand the changing nature of policing practices, initiatives, local crime trends or other relevant factors throughout the country.Footnote 30
Analytical articles published by Statistics Canada offer additional context with respect to larger crime trends, such as changes in property crime and hate crime at the beginning of the COVID-19 pandemic, or online child sexual exploitation.
Footnotes in data tables and analyses provide important information on changes in legislation, local policing strategies, or complex types of crime involving cyber technology or organized crime elements.
For additional contextual information within and outside the criminal justice system, see the following resources:
- Census Profile, 2021 Census of Population
- Centre for Municipal and Local Data
- Rural Canada statistics
- Crime and justice statistics
Looking for more information?
For more information on the Crime Severity Index and other police-reported crime statistics, please contact the Canadian Centre for Justice and Community Safety Statistics at statcan.ccjcss-ccsjsc.statcan@statcan.gc.ca.
Data tables at various geographic levels are also available free of charge through the Statistics Canada website.
The following are methodological reports available either through the Statistics Canada website or from the Canadian Centre for Justice and Community Safety Statistics (internal reports):
- Cormak, Andrew and Tracy Tabuchi. 2020. Updating the Police-Reported Crime Severity Index: Calculating 2018 Weights. Statistics Canada. Working paper SSMD-2020-01E .
- Babyak, Colin, Aidan Campbell, Rose Evra and Sarah Franklin. 2013. Updating the Police-Reported Crime Severity Index Weights: Refinements to the Methodology. Statistics Canada. Working paper HSMD-2013-005E.
- Babyak, Colin, Asma Alavi, Krista Collins, Amanda Halladay and Dawn Tapper. 2009. The Methodology of the Police-Reported Crime Severity Index. Statistics Canada Catalogue no. HSMD-2009-006E/F.
- Wallace, Marnie, John Turner, Colin Babyak and Anthony Matarazzo. 2009. Measuring Crime in Canada: Introducing the Crime Severity Index and Improvements to the Uniform Crime Reporting Survey. Statistics Canada Catalogue no. 85-004-X.