Illegal Firearm Availability and Violent Crime in Urban City American Society of Criminology Chicago, IL November 16, 20

1. Illegal Firearm Availability and Violent Crime in Urban City American Society of Criminology Chicago, IL November 16, 2012 Sung-suk Violet Yu, Ph.D Assistant Professor John Jay College of Criminal Justice Jesenia Pizarro, Ph.D Associate Professor Michigan State University

2. Prior Research Research suggests 4 possible relationships between firearms and crime: • Increasing firearm availability increases total crime • Increasing firearm availability increases crimes committed with firearms • Increasing firearm availability reduces crime • Increasing firearm availability is unrelated to crime Overall, the 2nd propositions has received the most support suggesting an instrumentality effect where the availability of firearm is related to levels of gun and violent crime (Altheimer, 2008).

3. Gaps in the Literature • The Relationship between availability of firearms and crime are often examined at larger spatial units (i.e., states, counties, or cities) • Most often use legal firearm ownership • Different dynamics • Different populations

4. Current Study • Purpose: The present study examines the relationship between illegal firearms and index crime. • Research Question: Is the presence of illegal firearms related to the prevalence of gun involved violence, no-gun violence, or property crime?

5. Current Study • Study area: Newark, NJ • Police places high priority in removing illegal firearms on the street • Recovered firearms used as a performance measure • Therefore, recovered firearms in Newark are more likely to reflect availability of illegal firearms on the street than other cities where lower priority is placed on the issue

6. Methodology: Analytical Approach • Unit of analysis: Census Block Groups (N=225) • Negative binomial regression • DVs: index crime was re-categorized as below: • Violence with gun (use or presence) • Violence without guns (no gun observed) • Property crime (burglary, auto related theft, and theft) • Control variables: • Spatial lag of DVs were created using Queens spatial weight matrix to address spatial autocorrelation • Total residents • Total businesses

7. Methodology: Variables • IVs: • Recovered illegal firearms • Structural variables - Non-Hispanic Black, Hispanic, foreign-born, Males aged from 18 to 29 - Less than high school education, male unemployment, female unemployment - Vacant housing units, female householder with children, families below poverty line

8. Principal Component Analysis (PCA):Structural Variables • Extracted two factors from 2000 census (76.5%) • PCA1 (Census): Hispanic, Foreign-born, Males aged from 18 to 29, and People over 25 with less than high school education • PCA2(Census): Vacant housing units, Female householder with children • Excluded variables from PCA due to: • Low commonality: number of male unemployed, non-Hispanic Black • Complex structure : family below poverty, female unemployment

9. Methodology: Models and Effect size • Three additive models • Model 1: Recovered weapons + spatial lag • Model 2: Total residents and total business • Model 3: Structural variables • Effect size: Incidence rate ratio (IRR) • For factors and spatial lag, SD is used to present IRR • For other count variables, one unit is used to present IRR • Ex) IRR = 1.5 (50% increase by one unit change) • IRR = 0.5 (50% decrease by one unit change)

10. Table 1: Crime in Newark, 2005 – 2007 (N=225)

11. Table 2. Gun violence and recovered firearms * = p<.05, ** = p<.01, ***=<p.001

12. Table 3. No-gun violence and recovered firearms * = p<.05, ** = p<.01, ***=<p.001

13. Table 4. Property crime and recovered firearms * = p<.05, ** = p<.01, ***=<p.001

14. Finding Summary • Spatial clustering of crime • Illegal firearm availability is associated with • violence with gun • violence without gun • property crimes • One unit increase in recovered firearm is expected to increase both gun and no-gun violence by 4% while controlling for other variables. For property crime, it was 2%

15. Finding Summary • However, differences emerged among them when looked at structural correlates • Gun violence: • Census PCA1 (Hispanic, foreign-born, males 18 to 29, less than high school) was associated with decreased gun violence • Male unemployment was associated with decreased gun violence • No-gun violence: • Census PCA2 (Vacant housing units, Female householder with children) is associated with increase no-gun violence

16. Implications: • Firearm availability is related to overall crime (gun violence, non gun violence, and property crime). • Gun violence, no gun violence appear stem from dissimilar structural conditions • Crime Prevention Initiatives should focus on both limiting the availability of firearms in the street, while at the same time the structural conditions that contribute to residents to seek out illegal firearms

17. Future Studies: • Effects of unit of analysis on findings? • PCA analysis • Different ways of data reduction? • How to better measure structural conditions in cities like Newark?

18. Illegal Firearm Availability and Violent Crime in Urban City American Society of Criminology Chicago, IL November 16, 2012 Sung-suk Violet Yu, Ph.D Assistant Professor John Jay College of Criminal Justice Jesenia Pizarro, Ph.D Associate Professor Michigan State University