title: Effects of undercover police stings of gun dealers on the supply of new guns to criminals.
abstract: OBJECTIVE
  To assess the effects of undercover police stings and lawsuits against gun dealers suspected of facilitating illegal gun sales in three US cities (Chicago, Detroit, Gary) on the flow of new firearms to criminals.
  
  
  METHODS
  An interrupted time series design and negative binomial regression analyses were used to test for temporal change in the recovery of guns used in crimes within one year of retail sale in both intervention and comparison cities.
  
  
  RESULTS
  The stings were associated with an abrupt 46.4% reduction in the flow of new guns to criminals in Chicago (95% confidence interval, -58.6% to -30.5%), and with a gradual reduction in new crime guns recovered in Detroit. There was no significant change associated with the stings in Gary, and no change in comparison cities that was coincident with the stings in Chicago and Detroit.
  
  
  CONCLUSIONS
  The announcement of police stings and lawsuits against suspect gun dealers appeared to have reduced the supply of new guns to criminals in Chicago significantly, and may have contributed to beneficial effects in Detroit. Given the important role that gun stores play in supplying guns to criminals in the US, further efforts of this type are warranted and should be evaluated.
authors.affiliation: Center for Gun Policy and Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205-1996, USA. dwebster@jhsph.edu
authors.forename: D W
authors.initials: DW
authors.lastname: Webster
authors.forename: M T
authors.initials: MT
authors.lastname: Bulzacchelli
authors.forename: A M
authors.initials: AM
authors.lastname: Zeoli
authors.forename: J S
authors.initials: JS
authors.lastname: Vernick
mesh_terms: D016010:Binomial Distribution; D003415:Crime / Q000706:statistics & numerical data*; D005389:Firearms / Q000331:legislation & jurisprudence* / Q000706:statistics & numerical data; D006801:Humans; D035846:Law Enforcement / Q000379:methods; D012044:Regression Analysis; D014481:United States