According to the FBI report, there were 20 active shooting incidents in the US in 2017. During the shootings, 138 people were killed, the first time in US history that the shooting death toll has risen above 90 in one year.
The FBI defines an active shooter as someone who is actively killing or attempting to kill people in a populated area, Sputnik reported.
"Am I surprised by the increase? No," said former FBI agent James Gagliano, USA Today reported.
"Part of it is these individuals who see one gunman on the news and the think, 'Wow, if they did this, I can do it, too,'" he said, adding. "It's a vicious circle and for the most part after these incidents, nothing changes. We all retreat to our corners and bicker."
Last year's death toll was high due in part to a shooting at the Route 91 Harvest Festival in Las Vegas, which killed 58 people and injured hundreds more.
However, according to Ron Hosko, a former assistant FBI director, the high statistic recorded by the FBI might simply be an outlier.
"I think-and hope-this is just a statistical anomaly," Hosko said. "The more time that goes by, the more we'll be able to tell if this is a rise or just simply the numbers fluctuating," adding that, "there's a risk of making too much out of spikes and valleys."