The rhetoric on social media following the killing of health care CEO Brian Thompson in New York earlier this month is “extremely troubling,” US Homeland Security Secretary Alejandro Mayorkas said.
“It speaks to what's really boiling over here in this country, and unfortunately we're seeing that play out in the violence, the domestic violent extremism that exists,” he told CBS' Face the Nation on Sunday.
Some on social media praised Luigi Mangione, the man accused of shooting Mr Thompson, and shared their anger at America's private health insurers.
Mayorkas said he was “disturbed 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 the largest US health insurer UnitedHealthcare, was shot dead outside a Manhattan hotel early on December 4, sparking a massive manhunt for the killer.
Mr. Mangione, 26, was arrested days later in Pennsylvania and flown to New York, where he faces federal and state charges, including first-degree murder in support of terrorism.
Investigators charge him with targeted killing, citing evidence that suggests a long-standing animosity toward the American health care industry. On social media, support for Mr. Mangione is often accompanied by complaints and complaints about the health insurance industry.
“We've been concerned about the rhetoric on social media for some time,” Mayorkas said Sunday. “We have seen hateful narratives. We have seen accounts of anti-government sentiment. We have seen 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 “incite some people to violence.”
“It's something we're very concerned about,” he said. “This is a heightened threat environment.”
But the 65-year-old, whose tenure at the head 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 in federal custody at the Metropolitan Detention Center Brooklyn, the same facility where Sean “Diddy” Combs is being held.
He is likely to be assigned a roommate and have daily visits from medical and psychological services, law enforcement sources told the BBC's US partner CBS.
Although New York does not have the death penalty, he faces four federal charges, including murder and stalking, that could make him eligible for the punishment. He also faces multiple state charges.
He is expected to be arraigned on those state charges in New York on Monday. Mr. Mangione faces 11 charges, including first-degree murder and murder as a terroristic offense.