Despite the seemingly ever-present debate over gun-control laws, little data exists on the prevalence of crimes committed by people using guns.
Most studies of gun crimes originate in academia, like a Boston University study published in the American Journal of Public Health in November that tracked the relationship between gun ownership and firearm homicide rates in the country over 30 years.
The best data available on gun crimes is the annual mortality report issued by the Centers for Disease Control and Prevention's National Center for Health Statistics. But that report only includes deaths from guns.
The agency's most recent report contains firearm deaths for 2010.
That year, 31,672 people were killed by firearms nationwide. That's the highest number over a 10-year span and up 7.1 percent from 2001. Meanwhile in Illinois, 1,056 were killed by firearms in 2010, according to the Illinois Department of Public Health.
That's down 17.2 percent from 2001.
While the majority of firearm deaths nationally are suicides -- 19,392 in 2010 -- in Illinois, homicides account for the majority of firearm-related deaths.
In 2010, 573 homicides in Illinois were committed with a gun, according to the state mortality report.
That's also down 22.5 percent from 2001.
However, the report indicates that one out of every 20 firearm-related homicides in the country in 2010 happened in Illinois.
Accidental, undetermined and legal gun deaths make up a small portion of the national and state mortality rates, according to the reports.
While local law enforcement is required to submit annual crime statistics to the Illinois State Police, which funnels them on to the FBI for use in its annual Uniform Crime Report, those statistics do not parse out gun crimes. Illinois State Police spokeswoman Monique Bond said she is unaware of any study the agency has done on gun crimes and acknowledged the state public safety agency does not require local police to track whether crimes such as homicide, assault or robbery were committed with a gun.
And because court clerks are not subject to the state's Freedom of Information Act, it is difficult to obtain data on weapons charges. Though a request to Lake County Circuit Court Clerk Keith Brin was rejected, DuPage County Circuit Court Clerk Chris Kachiroubas provided a year's worth of data on cases involving all weapons, including guns.
However, court records also are incomplete because weapons violations sometimes are not charged as prosecutors pursue more serious charges or drop a weapons-related accusation as part of a plea agreement.