A new study - produced through a join effort between the Violence Prevention Research Program at University of California-Davis and the Center for Gun Policy and Research at Johns Hopkins University - reveals that after Colorado passed a universal background check law in 2013, background checks for private firearm transfers did not significantly increase. The new study begins with a pretty simple hypothesis: if a state passes a law requiring universal background checks (UBCs) for private firearm transfers, then number of background checks performed should increase. “The overwhelming majority of all firearms used for criminal purposes, some 80 percent, are acquired through private party transactions,” writes Alvaro Castillo‐Carniglia, the study's lead author. “By expanding background checks to include private‐party transfers, there is a higher chance that these policies will make it harder for felons and other prohibited persons to acquire firearms and commit violent crimes.” However, the study's own results seem to disagree. After accounting for the controls, the researchers found no statistically significant increase in background checks performed in post-UBC Colorado. While the researchers noticed an increase following Delaware's UBC law, there was no significant increase in background checks performed after Colorado's law went into effect in 2014. The study posits that this could be the result of noncompliance and non-enforcement. On the non-compliance front, the study's authors correctly point to the fact that many retailers refused to process private party background checks immediately after the law went into effect. Others still, to this day, charge $40 or more for private transfer background checks when the same background check for a store-bought firearm costs just $7. The reasoning, from a store owner's perspective, is simple. Gun stores are not charities. Every minute that an employee spends on processing a private transfer is a minute they are not spending moving store merchandise. As a result, firearm dealers in Colorado charge private transfers extra to process their background checks. However, the study's authors leave out a important clause within the law that exempts certain private sales from the background check requirements, specifically that curio and relic guns are explicitly excluded. That means that private parties transferring firearms that are 50-years-old or older or have been determined by the Bureau of Alcohol, Tobacco, Firearms, and Explosives to have special historical value are exempt under Colorado's 2013 background check law. While the majority of tables selling firearms at Colorado gun shows are run by licensed dealers, many, if not most, of the private unlicensed firearm sellers are selling older firearms that are exempted within the law. While these might account for a minority of total gun sales at gun shows, they tend to account for a majority of unlicensed private party sales at these shows. Additionally, the study mentions non-enforcement of Colorado law as a reason for not finding a noticeable or significant increase. To rectify this, the authors recommend that Colorado's background check law be strictly enforced. However, the study seems to gloss over just how unenforceable the law is. Without a statewide gun registry, it is impossible to enforce.