The heroism attributed to suspect Luigi Mangione is alarming

The rhetoric on social media following the killing of Health Care CEO Brian Thompson in New York earlier this month has been “extremely troubling,” says U.S. Homeland Security Secretary Alejandra Mayorkas.

“It speaks to what’s really bubbling here in this country, and unfortunately we’re seeing it manifest in the violence, the violent domestic extremism that exists,” he told CBS’ Face the Nation on Sunday.

Some on social media singled out Luigi Mangione, the man accused of shooting Mr Thompson, and shared their anger at America’s private health insurance companies.

Mayorkas said he was “alarmed by the heroism attributed to the alleged killer of a father of two on the streets of New York.”

Mr. Thompson, the 50-year-old chief executive of UnitedHealthcare, the largest US health insurer, was shot dead outside a Manhattan hotel in the early evening of December 4, sparking a massive manhunt for the killer.

Mr. Mangione, 26, was arrested days later in Pennsylvania and taken to New York, where he faces both federal and state charges, including first-degree murder in furtherance of terrorism.

Investigators accuse him of targeted killing, pointing to​​​​ evidence of a long-standing animosity toward the U.S. health care industry. On social media, support for Mr. Mangione was often accompanied by insults and complaints about the health insurance sector.

“For some time, we have been concerned about the rhetoric on social media,” Mayorkas said on Sunday. “We have seen narratives of hate. We have seen stories of anti-government sentiment. We saw personal grievances in the language of violence.”

Mayorkas, whose Department of Homeland Security is partly responsible for protecting Americans from domestic terrorism, said his department sees a “wide range of narratives” that “drive some people to violence.”

“That’s something we’re very concerned about,” he said. “This is a high-risk environment.”

But the 65-year-old, whose time at the helm of the department ends next month, stressed that Mr Thompson’s killing was “the act of an individual (and) does not reflect the American public”.

Mr Mangione will remain behind bars in New York as his lawyers said last week they would not apply for bail. He is being held in federal custody at the Brooklyn Detention Center, the same facility where Sean “Diddy” Combs is being held.

Law enforcement sources told the BBC’s US partner CBS that he is likely to be assigned a roommate and will receive daily visits from medical and psychological services.

Although New York does not have the death penalty, he faces four federal charges, including murder and stalking, that could make him eligible for execution. He also faces multiple state charges.

He is expected to be arraigned on the state charges in New York on Monday. Mr. Mangione is charged with 11 counts, including first-degree murder and murder as a terrorist offense.