There are fewer school shootings in states that have tighter gun control laws and spend more on mental health care and public education, a new study finds.
Close to 33,000 people are killed and another 81,000 are injured by gun violence every year in the United States, the researchers said.
The number of school shootings is particularly high. There were 44 such incidents between 1996 and 2008, the study authors said.
In the new study, the researchers analyzed media reports on 154 school shootings that occurred in the United States between 2013 and 2015.
On average, there was one school shooting every week over the course of the three years, and the number of these incidents rose every year during the study period. There were 35 in 2013, 55 in 2014, and 64 in 2015, according to the report.
In all, 84 people — including 27 shooters — died, while another 136 people were injured, the findings showed. More than half of the school shootings occurred in publicly funded schools.
Thirty-nine states had at least one school shooting during the study period, while 11 had none: Alaska, Connecticut, Hawaii, New Hampshire, New Jersey, New York, North Dakota, Rhode Island, Vermont, West Virginia and Wyoming.
Thirty-four of the states with school shootings had fewer than 10 incidents, but the numbers were higher in Florida (14), Georgia (15), North Carolina (12), Tennessee (10) and Texas (14), the investigators found.
School shootings were less likely to occur in states that had mandatory background checks for gun and ammunition purchases, spent more on mental health services and K-12 education, and had a larger proportion of the population living in towns and cities, according to the report.
But the researchers noted that this was an observational study and could not prove that tighter gun laws or other factors reduced the number of school shootings.
The report was published online Dec. 6 in the journal Injury Prevention.
The rising number of school shootings in the United States highlights the need for a national registry to track mass and school shootings, in order to learn more about the causes and effects of these events, researcher Bindu Kalesan said in a journal news release. She is an assistant professor in the Center for Translational Epidemiology and Comparative Effectiveness Research at Boston University School of Medicine.
The U.S. Centers for Disease Control and Prevention offers data and statistics on school violence.