The shooting on Monday in Vermont near the Canadian border followed the surveillance of an armed couple who dressed in black tactical-style clothing.

As the sprawling investigation unfolds, here’s an overview of the key figures involved and their alleged connections.

An internal memo shows that Mexican cartels are ordering cartel members to attack Border Patrol agents with explosives and kamikaze drones.

Mexican drug cartels are reportedly using kamikaze drones and explosives to target US Border Patrol agents as the Trump administration intensifies its crackdown on illegal immigration. An internal memo warns agents to remain alert and wear protective gear.

Mexican drug cartels are reportedly planning drone attacks on US Border Patrol agents in response to Trump's border policies, as revealed in an internal memo.