A 21-year-old man from Butler County, Pennsylvania, has been arrested and charged with plotting a mass casualty attack in support of ISIS. The FBI intervened after discovering his intentions, which included the purchase of a rifle and 190 rounds of ammunition. The man allegedly pledged allegiance to ISIS and was found to be preparing for a violent attack. Authorities noted that this arrest follows an ongoing investigation into threats linked to terrorism, particularly around significant anniversaries such as 9/11. The suspect is now facing federal charges for his actions and intent to commit terrorism.