A report conducted by the Congressional Research Service found a consistent increase in the annual rate of public mass shootings since the 1970s.
The report, released July 30, analyzed “mass shooting data” from 1999 to 2013 and “mass public shooting” data from 1970 to 2013. The data is predominantly based on Supplementary Homicide Reports compiled by the FBI and data provided by criminologist Grant Duwe.
Researchers found there was an average of 1.1 mass public shootings annually in the 1970s, but that figure more than tripled by the 1990s to 4 incidents a year.
The rate hasn’t stopped climbing. Between 2010 and 2013 there was an average of 4.5 mass public shootings a year, with an average of 7.4 victims murdered and 6.3 wounded in each shooting.
Mass public shootings are defined by the FBI as the killing of four or more people with firearms in a public setting.
Researchers also called for Congress to direct government agencies to improve the collection of multiple-victim homicide statistics.
Specifically, the report wants improved collection of data on the following:
- offender acquisition of firearms
- types of firearms used
- amounts and types of ammunition carried and shots fired
- killed and wounded counts
- offender histories of mental illness and domestic violence
- victim-offender relationships
The report found that one of the problems of keeping count of these incidents is that different agencies and organizations have different definitions of terms like “mass killing,” “mass murder” and “mass shooting.”
Overall, “offenders committed at least 317 mass shootings, murdered 1,554 victims, and nonfatally wounded another 441 victims entirely with firearms” from 1999 to 2013.
