Federal agents fired tear gas to disperse a crowd during a tense standoff on Chicago's far South Side Tuesday afternoon.

Video captured the moment a heavy federal presence was seen at a Chicago intersection, with armed agents, many masked or ...

Sen. Bill Nelson, D-Fla., on Wednesday revealed chilling details about how the shooter suspected of killing at least 17 people at a high school in Parkland, Fla., brought a gas mask and smoke grenades ...

WOBURN, Mass. (WHDH/CNN Newsource/WKRC) - A courthouse had to be evacuated after a man in a gas mask and a helmet attempted to storm the building and attacked a security guard with pepper spray.

New video shows the moments a man in a gas mask walks up to a courthouse in Woburn, Massachusetts, and forces his way inside while pepper-spraying officers on Monday. He was quickly tackled and ...