Officials from the Department of Homeland Security visited a Pittsburgh synagogue months before a gunman shot and killed 11 individuals on Saturday, the agency’s top chief said on Sunday.

“As recently as March we conducted a site visit here with our protected security advisers in the area,” DHS Secretary Kirstjen Nielsen said on “Fox News Sunday.”

Nielsen joined President Trump in condemning the action as a “pure act of evil.” The shooting suspect, 46-year-old Robert Bowers, faces several federal charges, including for hate crimes, and remains in custody.

The incident occurred just a day after federal officials apprehended a Florida man connected to the mailing of pipe bombs to prominent Democrats. Coupled together with the increasing hostile behavior toward elected officials in recent months, the events have spurred a national dialogue over whether the political rhetoric in the country has risen to dangerous levels.

[Related: Eric Trump: Pittsburgh synagogue shooter doesn't 'represent the Right']

Nielsen, along with other GOP leaders, was verbally harassed in a restaurant earlier this year by protesters who opposed the Trump administration’s decision to separate migrant children from their parents at the U.S.-Mexico border. Asked if she thought those actions were within the protesters’ right to free speech, Nielsen said anyone “who uses the First Amendment to threaten or commit an act of violence will not be tolerated.”

“I do not support that,” she said. “To the extent that folks exercise their First Amendment rights, that. is protected in our country. But there is a line.”

Nielsen declined to say whether Trump bore any responsibility for the recent hostile behavior. Trump has used politically charged rhetoric against reporters, including referring to media as the "enemy of the people." He most recently praised Montana GOP lawmaker Greg Gianforte for body-slamming a reporter earlier this year.