Objective The available evidence suggests that more restrictive state firearm sales laws can reduce criminal access to guns. California has firearm-related laws that are more stringent than many other states and regulates its retail firearms dealers to a unique degree. This research seeks to examine the effect of more restrictive state gun laws and regulations on the illegal diversion of guns to criminals.

Design Survival analyses are used to determine whether state firearm sales laws, particularly California's legal context and regulatory regime, impact the distribution of time-to-crime of recovered firearms in that state relative to other US states.

Setting USA.

Subjects 225 392 traced firearms, where the first retail purchasers and the gun possessors were different individuals, recovered by law enforcement agencies between 2003 and 2006.

Results The increased stringency of state-level firearms laws and regulations leads to consistently older firearms being recovered. California was associated with the oldest recovered crime guns compared with guns associated with other states. These patterns persisted regardless of whether firearms were first purchased within the recovery state or in another state.

Conclusions These findings suggest that more restrictive gun sales laws and gun dealer regulations do make it more difficult for criminals to acquire new guns first purchased at retail outlets.