The FBI has seen an increase in white supremacist terror suspects since the fall, a senior bureau counterterrorism official said Thursday.
The bureau did not provide exact statistics, but said there has been a “significant” increase in the number of cases and arrestsl. Arrests were estimated to increase by as much as 40 percent in the past year, the official said.
However, the official cautioned exact numbers are difficult to measure. In recent years the FBI has rebranded certain cases making comparisons to previous years somewhat challenging. The bureau has recategorized some of the cases so it can have more clarity in how it views cases, the official said.
For example, bombing suspect Cesar Sayoc was identified as a white supremacist, but his targets were politically, not racially, motivated. Such cases could fall into either category.
One reason for the increase is a rise in plans for copycat and retaliation plots after a successful attack, the official said.
The recent arrest of U.S. Army veteran Mark Steven Domingo highlights a rise in revenge plots. Mr. Domingo was arrested last month planning a massive attack in Long Beach, California, as retaliation for the New Zealand mosque shootings that left 51 dead.
Another reason for the increase is the speed in which suspects are being radicalized online, according to the bureau.
Overall, the bureau has about 5,000 open terrorism investigations in the United States and abroad with roughly 850 categorized as domestic terrorism. That includes a wide variety of cases including militant environmental and animal rights groups, abortion extremists on both sides and racially-motivated domestic terrorists.