About 1,500 Minnesota National Guard troops went from standby to active following the second fatal shooting by federal agents in Minneapolis on Saturday.

Gov. Tim Walz activated the troops Saturday after agents shot and killed 37-year-old Alex Jeffrey Pretti, an intensive care unit nurse and U.S. citizen. Homeland Security said shots were fired in defense, and Pretti was armed.

There is video as well as dispute about specifics.

Brig. Gen. John Manke, adjutant general of Minnesota National Guard, said at a news conference that guard troops' first order of business would be to help provide security at the Whipple Federal Building, home to the federal court and U.S. Immigration and Customs Enforcement detention center.

Soldiers have been on standby for nearly a week, Manke said, preparing in the Twin Cities area to respond following a request from Hennepin County sheriff’s officials.

At the same news conference, Walz said he understood frustrations and reiterated his call for federal officers to leave the community.

“I want to use this opportunity to stress to Minnesotans the frustration you have,” Walz said. “They killed a man, created chaos, pushed down protesters indiscriminately and then left the scene, and were left to clean up. I understand the anger. I understand trying to parse who are the law enforcement on the scene when you got there after a man was killed is difficult for the folks who are out there. We can handle this, and Minnesotans can express their First Amendment rights and have our folks on the streets and get these people out of here.”

Homeland Security Secretary Kristi Noem on Saturday said Pretti was attempting to impede lawmen in their duties.

"This individual showed up to impede a law enforcement operation and assaulted our officers," Noem said at a news conference. "They responded according to their training and took action to defend the officer's life and those of the public around him."