Data for 2007 on the incidence of homicides and the debilitating effects of gang violence in California show the devastating role that firearms play in such violence. California homicide data covering 1998 to 2007 show that the percentage of homicides in which the contributing circumstance was gang-related increased from 22 percent to 32.7 percent over this period. One category of California data source on firearms and/or gangs consists of the California Department of Justice databases that contain information related to firearm purchases, possession, or eligibility for firearm purchases. A second data source consists of select California Department of Justice databases that contain crime, gang, or firearms information unrelated to firearm transfers. A third data source is composed of select California Department of Public Health databases that contain crime, gang, or firearm information unrelated to firearm transfers. Each of the databases within the three aforementioned broad categories are described according to the data it contains and who is authorized to access the information. Data from the VPC survey of California law enforcement agencies regarding their collection of information on gang violence found that of the 136 responding agencies, 66 reported that they "collect information linking specific firearms to use or possession by individuals involved in gang violence." The report concludes that regardless of the approach taken, there is a desire and need for more accurate and comprehensive data on youth gang violence and firearms. 45 notes