Active attacks occur for a variety of reasons, sometimes they are planned and other times not. Here, we show the timing of active attacks from 2000 to 2023, a critical element for premeditated attacks with the goal of maximizing casualties. As the plots demonstrate, some dimensions of time are more informative than others.
By Year
There appears to be more events in the last five years (mean = 46) than the first five years (mean = 8) or second five years (mean = 16); however, this may be an artifact of media coverage. Attacks that occurred during the first part of this data collection period likely did not get the national coverage that they do now. Furthermore, technology and search engines have improved dramatically over the 24 years of this data collection period.
By Month
In contrast to the obvious upward trend in attacks across years, there appear to be only a modest trend related to months of the year. Active Attacks tend to peak during the warmer months of the year (e.g., April through August account for 47.3% of attacks), though this trend is not a strong one. The relationship with temperature is similar to trends observed for certain types of violent crime (e.g., aggravated assault, homicide) that also tend to peak during the warmest parts of the year.
By Day of the Week
Active attacks share no observable association with day of the week. This can be seen by the flat distribution of attacks across the week. So while there may be trends by year and month, attacks appear to be nearly equally likely on any given day of the week.
By Hour of the Day
Active attacks tend to cluster around midday. While attacks that begin at midday exactly are relatively infrequent (only 3.9% of attacks), the majority of attacks occur immediately before midday (8-11am hours account for 25.4% of attacks) or after midday (1-4pm hours account for 24.3% of attacks).
Many in the media attempt to create a profile describing the “average” attacker. The data do not support a profile beyond sex and number of attackers. Attackers were male 96.2% of the time. Furthermore, the attacker commits the attack by him/herself 97.5% of the time. Beyond these characteristics, attackers are somewhat more varied.
Attacker Race/Ethnicity
The racial/ethnic makeup of attackers roughly mirrored that of the general population, though Caucasians were under-represented and African Americans were over-represented. Most attackers were either Caucasian (46.3%) or African American (30%). All other racial/ethnic groups (e.g., Latino, Asian, Middle Eastern) only accounted for around a quarter of attackers (23.7%).
Attacker Age
While the median age of attackers was 31 years old, attackers ranged in age from 12 to 88. Attackers in their twenties were the most plentiful group compared to any other decade of life. The age-trend of attackers adheres to the classic “age-crime curve” observed for nearly every crime type, peaking in late adolescence/early adulthood and steadily declining throughout the rest of the life course.
Weapon Type
Active attacks can be carried out using any weapon though, in reality, only a very small minority of attacks (6.2%) were carried out using weapons other than firearms (e.g., knife, vehicle). Among types of firearms, handguns made up a clear majority (56.1%), while rifles (e.g., AR15s) and shotguns were used in 28.4% and 8.1% of the time, respectively.