Examination of Crime Guns and Homicide in Pittsburgh, Pennsylvania, 1987-1998

This study examined spatial and temporal features of crime
guns in Pittsburgh, Pennsylvania, in order to ascertain how gun
availability affected criminal behavior among youth, whether the
effects differed between young adults and juveniles, and whether that
relationship changed over time. Rather than investigating the general
prevalence of guns, this study focused only on those firearms used in
the commission of crimes. Crime guns were defined specifically as
those used in murders, assaults, robberies, weapons offenses, and drug
offenses. The emphasis of the project was on the attributes of crime
guns and those who possess them, the geographic sources of those guns,
the distribution of crime guns over neighborhoods in a city, and the
relationship between the prevalence of crime guns and the incidence of
homicide. Data for Part 1, Traced Guns Data, came from the City of
Pittsburgh Bureau of Police. Gun trace data provided a detailed view
of crime guns recovered by police during a two-year period, from 1995
to 1997. These data identified the original source of each crime gun
(first sale to a non-FFL, i.e., a person not holding a Federal
Firearms License) as well as attributes of the gun and the person
possessing the gun at the time of the precipitating crime, and the
ZIP-code location where the gun was recovered. For Part 2, Crime
Laboratory Data, data were gathered from the local county crime
laboratory on guns submitted by Pittsburgh police for forensic
testing. These data were from 1993 to 1998 and provided a longer time
series for examining changes in crime guns over time than the data in
Part 1. In Parts 3 and 4, Stolen Guns by ZIP-Code Data and Stolen Guns
by Census Tract Data, data on stolen guns came from the local
police. These data included the attributes of the guns and residential
neighborhoods of owners. Part 3 contains data from 1987 to 1996
organized by ZIP code, whereas Part 4 contains data from 1993 to 1996
organized by census tract. Part 5, Shots Fired Data, contains the
final indicator of crime gun prevalence for this study, which was 911
calls of incidents involving shots fired. These data provided vital
information on both the geographic location and timing of these
incidents. Shots-fired incidents not only captured varying levels of
access to crime guns, but also variations in the willingness to
actually use crime guns in a criminal manner. Part 6, Homicide Data,
contains homicide data for the city of Pittsburgh from 1990 to
1995. These data were used to examine the relationship between varying
levels of crime gun prevalence and levels of homicide, especially
youth homicide, in the same city. Part 7, Pilot Mapping Application,
is a pilot application illustrating the potential uses of mapping
tools in police investigations of crime guns traced back to original
point of sale. NTC. It consists of two ArcView 3.1 project files and
90 supporting data and mapping files. Variables in Part 1 include date
of manufacture and sale of the crime gun, weapon type, gun model,
caliber, firing mechanism, dealer location (ZIP code and state),
recovery date and location (ZIP code and state), age and state of
residence of purchaser and possessor, and possessor role. Part 2 also
contains gun type and model, as well as gun make, precipitating
offense, police zone submitting the gun, and year the gun was
submitted to the crime lab. Variables in Parts 3 and 4 include month
and year the gun was stolen, gun type, make, and caliber, and owner
residence. Residence locations are limited to owner ZIP code in Part
3, and 1990 Census tract number and neighborhood name in Part 4. Part
5 contains the date, time, census tract and police zone of 911 calls
relating to shots fired. Part 6 contains the date and census tract of
the homicide incident, drug involvement, gang involvement, weapon, and
victim and offender ages. Data in Part 7 include state, county, and
ZIP code of traced guns, population figures, and counts of crime guns
recovered at various geographic locations (states, counties, and ZIP
codes) where the traced guns first originated in sales by an FFL to a
non-FFL individual. Data for individual guns are not provided in Part
7.