The FBI released its Active Shooter report looking at the 14 years from 2000 through 2013. The report indicates several key elements based on the 160 incidents identified.
Increasing - The unfortunate news is that active shooter incidents are on the rise - 6.4 incidents per year (one every 2 months) in the first seven years compared to 16.4 incidents per year (more than 1 per month) for the most recent 7 years.
Location - Somewhat surprising - especially based on the media coverage - is the fact that an active shooter incident is almost twice as likely to happen in a commercial space (45.6%) as opposed to an educational space (24.4%).
Fast - Of the incidents where the duration could be ascertained (64), 69% of them end within 5 minutes - very fast paced.
Ending - In 40% of the incidents the shooter commits suicide. In 28% of the incidents law enforcement and the shooter exchange gunfire.
See the full report for more information.