Assuming access to guns, the top ten guns involved in crime in the U.S. show a definite tendency to favor handguns over long guns. The top ten guns used in crime, as reported by the ATF in 1993, were the Smith & Wesson .38 Special and .357 revolvers; Raven Arms .25 caliber, Davis P-380 .380 caliber, Ruger .22 caliber, Lorcin L-380 .380 caliber, and Smith & Wesson semi-automatic handguns; Mossberg and Remington 12 gauge shotguns; and the Tec DC-9 9 mm handgun. An earlier 1985 study of 1,800 incarcerated felons showed that criminals preferred revolvers and other non-semi-automatic firearms over semi-automatic firearms. In Pittsburgh a change in preferences towards pistols occurred in the early 1990s, coinciding with the arrival of crack cocaine and the rise of violent youth gangs. Background checks in California from 1998 to 2000 resulted in 1% of sales being initially denied. The types of guns most often denied included semiautomatic pistols with short barrels and of medium caliber. A 2018 study determined that California's implementation of comprehensive background checks and misdemeanor violation policies was not associated with a net change in the firearm homicide rate over the ensuing 10 years. A 2018 study found no evidence of an association between the repeal of comprehensive background check policies and firearm homicide and suicide rates in Indiana and Tennessee.