Assignment:
Create a "Data Matrix Table", using MS Word, as per the Resources Folder video link, and DISPLAY how this table may be the most pertinent data instrument used in contemporary police work.
Key Terms to know:
Data matrix: a rectangular table of variables and units from which data have been collected, such as individuals, organizations, crimes, that are organized into rows and columns
Tabular data: events that are not inherently geographic but that may contain geographic variables
Primary data: data collected specifically for the purposes of the analysis at hand
Databases Used in Crime Analysis
Crime Incident DB
Crime reports taken by police officers or other police personnel which contains the nature of the crime
The unit of analysis is the criminal incident; therefore, there is one record for each criminal incident
Variables used: Incident number / Date of report/ Type of crime
Arrest DB
An arrest report that includes information specific to the arrest of that individual Linked to the original crime report (if applicable)
The unit of analysis is the arrest, so there is one record for every arrest
Variables: Arrest number / Date of arrest
Calls for Service (2 Types)
Citizen-generated: citizen calls, officer responds, whether the reason is criminal or noncriminal
Officer-generated: police officer proactively identify activity in the field
Variables: Incident number / Date and time (received, dispatched, arrived, and cleared)
Type of call
Priority
Accidents
Incidents in which vehicles collide with people, property, or other vehicles.
Each record in an accident database contains information about one accident; therefore an accident is the unit of analysis
Variables: Accident number / Violations
Other Databases
Persons database: individuals involved in criminal incidents, including witnesses, victims, investigative leads, suspects, and arrestees. In this database, the unit of analysis is the individual.
Known offender database: information about individuals who have been convicted, not just arrested, for crimes in the local jurisdiction.
Primary Data Collection
Primary data collected from people:
Interviews tend to be more in depth because they allow clarification of issues and use follow up questions with the interviewee
Primary data collected from places
Used to systematically observe the physical features of a location
Direct observation refers to observing a location for a certain amount of time over several days or weeks (surveillance)
Data Considerations
"Reported" Activity
Certain types of activity tend to be reported more consistently or comes to the attention of the police more than others
May not provide the entire picture of a particular issue
Local and Federal Crime Data Standards
Uniform Crime Report (UCR)
NIBRS system (National Incident Based Reporting System)
Figures from local crime and arrest data databases will NEVER match the numbers reported to the FBI
Using Calls for Service Data to Study Crime Problems
Calls for service are more helpful in analyzing police officer activity and disorder activity than to study crime
Using Arrest Data to Study Crime Problems and Offenders
Arrests tend to reflect police activity
Arrests rates for certain crimes are extremely low and using a small number of offenders to understand the larger problem may be misleading