According to “United States Active Shooter Events from 2000 to 2010: Training and Equipment Implications” by J. Pete Blair and M. Hunter Martaindale from Texas State University:
- The most commonly used weapon (60 percent) by active shooters was a pistol.
- Attackers carried multiple weapons in 41 percent of the attacks.
- The active-shooter attacks ended before the police arrived 49 percent of the time.
- In 56 percent of the attacks that were still ongoing when police arrived, the police had to use force to stop the killing.
- The median number of victims killed is two. The median number of victims shot by the suspect is four.