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Description & Citation--Study No. 3145 | |
Bibliographic Description | |
| ICPSR Study No.: | 3145 |
|---|---|
| Title: | Gun Density, Gun Type, and the Dallas Homicide Rate, 1980-1992 |
| Principal Investigator(s): | Christopher S. Koper, Crime Control Institute |
| Funding Agency: | United States Department of Justice. National Institute of Justice. |
| Grant Number: | 94-IJ-CX-0038 |
| Bibliographic Citation: | Koper, Christopher S. GUN DENSITY, GUN TYPE, AND THE DALLAS HOMICIDE RATE, 1980-1992 [Computer file]. ICPSR version. Philadelphia, PA: Crime Control Institute [producer], 1998. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2001. |
Scope of Study | |
| Summary: | This study examined the relationships among trends in deadly gun violence, overall gun availability, and the availability of more lethal types of guns. Using firearms confiscated by the Dallas, Texas, police department from 1980 to 1992 as indicators of the types of guns circulating among criminal/high-risk groups, the project examined changes over time in Dallas' street gun arsenal and assessed the impact these changes had upon gun violence mortality in Dallas. The focus of the project was on the characteristics of the guns rather than their numbers. All confiscated firearms were analyzed and characterized according to basic weapon type and caliber groupings. Dates of confiscation were missing from the majority of the pre-1988 records, but by aggregating the gun data into bimonthly (Part 1) and quarterly (Part 2) time series databases, it was possible to estimate the bimonthly and quarterly periods of confiscation for most of the 1980-1992 records. Records that could not be assigned to bimonthly or quarterly periods were dropped. Confiscated firearms were grouped into basic categories based on stopping power (i.e., wounding potential), rate of fire, and ammunition capacity. The following measures were created for each bimonthly and quarterly period: (1) weapons with high stopping power (large guns), (2) semiautomatic weaponry (semis), (3) weapons combining high stopping power and a semiautomatic firing mechanism (large semis), (4) handguns with high stopping power (large handguns), (5) semiautomatic handguns (semi handguns), and (6) handguns combining high stopping power and semiautomatic firing (large semi handguns). Several violence measures were obtained from the Federal Bureau of Investigation's (FBI) Uniform Crime Reports Supplemental Homicide Reports and Return A (or Offenses Known and Clearances by Arrest) data files (see UNIFORM CRIME REPORTING PROGRAM DATA [UNITED STATES]: 1975-1997 [ICPSR 9028]). These measures were also aggregated at bimonthly and quarterly levels. Data from the Dallas Police Department master gun property file include total handguns, total semiautomatic handguns, total large-caliber handguns, total large-caliber semiautomatic handguns, total shotguns, total semiautomatic shotguns, total rifles, total semiautomatic rifles, and total counts and total semiautomatic counts for various calibers of handguns, shotguns, and rifles. Data that were aggregated using the FBI data include total homicides, gun homicides, total robberies, gun robberies, and gun aggravated assaults. The data file also includes the year and the bimonthly or quarterly period counter. |
| Subject Term(s): | assault weapons, crime reporting, firearms, gun ownership, gun use, handguns, mortality rates, police records |
| Geographic Coverage: | Dallas, Texas, United States |
| Time Period: | 1980 - 1992 |
| Date(s) of Collection: | 1994 |
| Unit of Observation: | Part 1: Bimonthly time period. Part 2: Quarterly time period. |
| Universe: | All guns confiscated by Dallas police from 1980 through 1992. |
| Data Type: | administrative records data, and event/transaction data |
| Data Collection Notes: | (1) Users are encouraged to obtain a copy of the Final Report for detailed information on the generation of these data and the project's time-series analysis. (2) The user guide and the codebook are provided by ICPSR as Portable Document Format (PDF) files. The PDF file format was developed by Adobe Systems Incorporated and can be accessed using PDF reader software, such as the Adobe Acrobat Reader. Information on how to obtain a copy of the Acrobat Reader is provided on the ICPSR Web site. |
Methodology | |
| Purpose of the Study: | Social scientists have rarely examined consequences stemming from the availability and use of differentially lethal guns, despite empirical and theoretical grounds for believing that some guns are more lethal than others. However, a number of recent studies have linked increases in homicides to the growing use of semiautomatic and/or high-powered firearms by criminals. These studies imply that gun violence is becoming more deadly due to the substitution of more lethal firearms for less lethal firearms. Using data from Dallas, Texas, for the period 1980-1992, this study examined the relationships among trends in deadly gun violence, overall gun availability, and the availability of more lethal types of guns. Using firearms confiscated by police as indicators of the types of guns circulating among criminal/high-risk groups, the project examined changes over time in Dallas's street gun arsenal and assessed the impact these changes had upon gun violence mortality in Dallas. The project also examined whether trends in the use of different types of guns predicted gun homicides better than a more traditional measure of overall gun density. |
| Study Design: | This study was based on information regarding approximately 58,000 guns confiscated by Dallas police from 1980 through 1992. The data include guns seized in association with arrests or other incidents as well as guns that were found or voluntarily turned in by citizens. The focus of the project was on the characteristics of the guns rather than their numbers. All confiscated firearms were analyzed and characterized according to basic weapon type and caliber groupings. Dates of confiscation were missing from the majority of the pre-1988 records, but by aggregating the gun data into bimonthly (Part 1) and quarterly (Part 2) time-series databases, it was possible to estimate the bimonthly and quarterly periods of confiscation for most of the 1980-1992 records. Records that could not be assigned to bimonthly or quarterly periods were dropped. Confiscated firearms were grouped into basic categories based on stopping power (i.e., wounding potential), rate of fire, and ammunition capacity. The following measures were created for each bimonthly and quarterly period: (1) weapons with high stopping power (large guns), (2) semiautomatic weaponry (semis), (3) weapons combining high stopping power and a semiautomatic firing mechanism (large semis), (4) handguns with high stopping power (large handguns), (5) semiautomatic handguns (semi handguns), and (6) handguns combining high stopping power and semiautomatic firing (large semi handguns). Several violence measures were obtained from the Federal Bureau of Investigation's (FBI) Uniform Crime Reports Supplemental Homicide Reports and Return A (or Offenses Known and Clearances by Arrest) data files (see UNIFORM CRIME REPORTING PROGRAM DATA [UNITED STATES]: 1975-1997 [ICPSR 9028]). These measures were also aggregated at bimonthly and quarterly levels. An added advantage to using the bimonthly and quarterly time points was that they provide robust gun measures that are less sensitive to random events that could conceivably distort the gun measures (such as drug busts, which might produce large caches of weapons). |
| Sample: | For the years 1984 through 1992, the data represent nearly 100 percent of the guns confiscated by Dallas police. For earlier years, the data represent approximately 85 to 95 percent of the records received from the Dallas police department. Preliminary work with the data suggested that there were very low rates of error with respect to the designation and recording of basic firearm characteristics. Less than 1 percent of the records in the master file had missing or obviously invalid (i.e., nonexistent) weapon type designations or caliber fields. The researcher recoded relatively small numbers of records corresponding to categories of weapons, which, based on available narrative descriptions in the database, appeared to represent systematic miscodes. After this initial inspection, records for air guns, blank guns, flare guns, toy guns, and other miscellaneous codes corresponding to weapons other than handguns, rifles, or shotguns were removed. However, any remaining true caliber and weapon type errors may have no consequence for analysis because the weapons were later grouped into broad semiautomatic/nonsemiautomatic and large/small caliber categories. Though a large majority of records in the master file included an indicator for the year during which the firearm was seized, the exact date of confiscation was missing for a substantial percentage of pre-1988 records. The approximate period of confiscation was estimated for the majority of early-year records based on an inspection of the service incident numbers, which ascended with confiscation dates. This estimation was accomplished with more accuracy and with less remaining missing data by using the bimonthly and quarterly aggregations. Records that could not be assigned to bimonthly or quarterly periods were dropped. There was no reason to believe that the guns excluded due to missing date information differed systematically from the other guns. Due to limitations in the data, it was not possible to take into account other potentially important factors, such as ammunition shape and jacketing, exact ammunition capacity, or barrel length. Justifiable homicides and negligent manslaughters were excluded from the homicide counts. |
| Data Source: | (1) Master gun property file from the Property/Auto Pound Section of the Dallas, Texas, police department, (2) Federal Bureau of Investigation's Uniform Crime Reporting Program data |
| Mode of Data Collection: | Data providing basic weapon type and caliber groupings were collected from a master gun property file provided by the Property/Auto Pound Section of the Dallas, Texas, police department. Offense counts were obtained using data from the Federal Bureau of Investigation's Uniform Crime Reporting Program. |
| Description of Variables: | Data from the Dallas, Texas, police department master gun property file include total handguns, total semiautomatic handguns, total large-caliber handguns, total large-caliber semiautomatic handguns, total shotguns, total semiautomatic shotguns, total rifles, total semiautomatic rifles, and total counts and total semiautomatic counts for various calibers of handguns, shotguns, and rifles. Data aggregated using the FBI data include total homicides, gun homicides, total robberies, gun robberies, and gun aggravated assaults. The data file also includes the year and the bimonthly or quarterly period counter. |
| Response Rates: | Not applicable. |
| Presence of Common Scales: | None. |
| Extent of Processing: | ICPSR reformatted the data and documentation. ICPSR also performed checks for undocumented codes, created codebooks, and generated SAS and SPSS data definition statements for this collection. |
Access and Availability | |
| Note: | A list of the data formats available for this study can be found in the summary of holdings. Detailed file-level information (such as LRECL, case count, and variable count) is listed in the file manifest. |
| Original ICPSR Release: | 2001-05-09 |
| Version History: | The last update of this study occurred on 2005-11-04. |
| 2006-03-30 - File CB3145.ALL.PDF was removed from any previous datasets and flagged as a study-level file, so that it will accompany all downloads. | |
| 2005-11-04 - On 2005-03-14 new files were added to one or more datasets. These files included additional setup files as well as one or more of the following: SAS program, SAS transport, SPSS portable, and Stata system files. The metadata record was revised 2005-11-04 to reflect these additions. | |
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