A study published on Thursday shows that national media coverage of mass killings and school shootings increases the likelihood that similar events will occur in the 13 days that follow a shooting.
The report that appears in the latest edition of PLOS One shows that 20-30 percent of mass shootings are the result of “infection,” and that the period of contagion is about 13 days. The risk of copycat shootings appears to fade after about two weeks.
Past shootings that resulted in less than three deaths appeared to not be contagious. The incidents that resulted in more fatalities, especially more than four, were deemed contagious due to national media coverage possibly planting the seeds of ideation in at-risk individuals to commit similar acts. Efforts by the media to not emphasize the killer’s name and portrait, however, may discourage additional shootings, reports LiveScience.
Researchers also found that states with a higher rate of gun ownership were more likely to have mass killings and school shootings, while those states that have greater restrictions on gun ownership have fewer mass shootings.
Mass killings involving firearms occur approximately every two weeks in the United States, while school shootings occur on average monthly.