Twenty years later, the Oklahoma City Bombing remains the deadliest mass casualty attack in US history carried out by domestic extremists on US soil. Domestic extremism, however, remains a persistent threat, and the United States has experienced violent ideologically-motivated criminal acts, both prior to and after the Oklahoma City attack. These acts include assaults, arsons, shootings, and use, or attempted use, of improvised incendiary and explosive devices, resulting in death, injury, and property damage. Many of the same motivations used by domestic extremists to justify their criminal acts in the mid-1990s—anti-government and anti-law enforcement sentiment; racial, ethnic, and religious hatred; and advocacy of violent conspiracy theories—continue to influence domestic extremists and their targeting choices in 2015.
According to the bulletin, the FBI and DHS “assess with high confidence that domestic extremism will remain a persistent threat through the end of 2015 and beyond. This assessment is based on prior patterns of behavior, current investigations, and observation of factors significant to domestic extremists.“
The bulletin also highlights that lone offenders will continue to pose the greatest threat of violence given how difficult it is for law enforcement to detect and prevent the lone wolf actors.