Research has revealed a dangerous trend in school bullying that suggests schools need to invest more into reducing all forms of bullying. According to Centers for Disease Control and Prevention (CDC) data from 2011, victims of bullying are sneaking an estimated 200,000 firearms and knives into U.S. high schools each year.

The conclusion was based on data collected and analyzed from more than 15,000 high schools across the country, in which students were asked if they had ever been bullied on school property in the past year and if they carried a weapon onto school grounds.

"With estimates of more than 200,000 victims of bullying carrying a weapon to high school, more effective prevention efforts and intervention strategies need to be identified," said principal investigator Dr. Lana Schapiro, in a press release. "The greatest focus should not just be on bullies, but on the victims of bullies most likely to carry a weapon and potentially use deadly force if threatened."

Once researchers looked at the relationship between those who had been bullied and if they brought a weapon onto school property, they found the threat in the 20 percent of high school students who reported being bullied. The data showed those who were victims of bullying were typically in lower grades, white and females.

“The CDC gave us the dots — we connected them. The data is staggering,” lead author Dr. Andrew Adesman, chief of developmental and behavioral pediatrics at Steven & Alexandra Cohen Children's Medical Center of New York, told NBC News.” Looking at these risk factors, it’s not hard to know who’s most likely to carry a weapon to school.” The findings from the study will be presented on Sunday at the Pediatric Academic Societies annual meeting in Vancouver, B.C.

If a student had multiple risk factors, such as if they were Caucasian and in their first year of high school, the likelihood of them bringing a weapon onto school property dramatically increased. Up to 28 percent of bullied students with one risk factor brought a weapon, while 62 percent of students with all three factors brought a weapon onto school property.

"Victims of bullying who have been threatened, engaged in a fight, injured, or had property stolen or damaged are much more likely to carry a gun or knife to school," said Adesman

According to the National Center for Education Statistics, during the 2009 to 2010 school year, 85 percent of U.S. public schools reported on-campus violence or crime, which totals to 1.9 million crimes in one year alone. The following 2010 to 2011 calendar year, there were 31 violent deaths associated with U.S. public schools. Of those, six were suicides.

"Large numbers of high school students report having been victimized by bullies and admit to carrying a weapon to school. Greater efforts need to be expended on reducing bullying in all of its many forms," Schapiro said in the release.

Not only were bullied students more likely to bring in a weapon, but those students who were victimized in multiple ways — whether it was cyber-bullied, threatened, or even beaten and berated — were up to 31 times more likely than those who were not bullied at all.

"Tragedies like the Columbine High School massacre have alerted educators and the public to the grave potential for premeditated violence not just by bullies, but by their victims as well," Adesman said. "Our analysis of data collected by the CDC clearly identifies which victims of bullying are most likely to carry a gun or other weapon to school."

Source: Schapiro et al. Association between Victims of Bullying and Weapon Carrying among High School Students in the United States. At The Pediatric Academic Societies Annual Meeting. 2014.