Tuesday’s violence may have marked the beginning of the end of the siege at Malheur. But the occupiers’ decision to take over the facility in the first place worries groups monitoring the self-styled militia organizations that have challenged federal authority in the West and across the country.

“The fact that they took over this federal building is a new thing,” said Heidi Beirich, who tracks militias and paramilitary organizations for the Southern Poverty Law Center. “In the past, obviously we’ve had standoffs, but they’ve been standoffs that involved feds sieging properties that are owned by the militants.”

Beirich said that the standoff at the Bundy ranch in 2014, during which the federal government walked away from confrontation, may have given the occupiers a sense that they could have success in their latest effort.

“Up to that point, I don’t think people — even as crazy as some of the people in the militia movement are — thought that you could put a gun to a federal officer and not get arrested and actually get what you wanted,” Beirich said.