UnitedHealthcare CEO shooting prompts questions about how to prevent copycats

As investigators continue to determine the motives and mindset that allegedly prompted Luigi Mangione to gun down UnitedHealthcare CEO Brian Thompson in New York nearly three weeks ago, there is concern among some criminologists about the long-term impacts that public assassination could cause.

"This is a unique event," Timothy Clancy, an assistant research scientist at the University of Maryland's National Consortium for the Study of Terrorism and Responses to Terrorism (START), told ABC News. "It brings together many things: the targeting of a singular individual; the combined anger and grievances that people have with the health care industry; the sensationalism of the manhunt."

That combination of factors, as well as ongoing coverage of the investigation and the suspect, could contribute to other people resorting to violence for similar grievances, Clancy and other criminology experts told ABC News. While experts said such potential radicalization is a rare occurrence for shootings involving lone actors, they also noted that there are proven strategies to prevent so-called copycats and to address the concerns of those who may be considering such action.

"We cannot use the police to fight the grievances. You have to do this right way to mitigate the violence," Clancy said.

Concerns over a lone actor whose actions may resonate with others

Mangione, 26, was charged Thursday in Manhattan federal court with four federal charges, including stalking, a firearms offense involving a silencer, and murder through use of a firearm, a charge that makes him eligible for the death penalty if convicted.

On Monday, Mangione pleaded not guilty in a Manhattan court to 11 state charges, including first-degree murder in furtherance of terrorism. A New York grand jury upgraded charges against Mangione last week to include the latter charge. He faces a maximum sentence of life in prison without parole if convicted of the state charges.

Mangione has not yet entered a plea in response to the federal charges and has been remanded to custody at the Metropolitan Detention Center in Brooklyn, New York until his next scheduled court appearance in January.

Judge Gregory Carro set the next hearing on the state charges for February 21. Mangione is also facing charges in Pennsylvania, where he was arrested, including forgery and allegedly possessing an unlicensed firearm.

Mangione's New York lawyer, Karen Friedman Agnifilo, said Thursday that her client was prepared to appear in state court and that the federal charges were unexpectedly introduced first, calling it "highly unusual."

On Monday following Mangione's plea, Agnifilo raised concerns that her client’s rights are being violated, alleging that the case is being politicized and that Mangione's right to a fair trial was "being prejudiced by some statements made by public officials,” calling out statements made by New York Mayor Eric Adams specifically, who called Thompson's murder an "act of terrorism."

Based on what investigators say they know about Mangione's alleged actions and motivations, he was a "lone wolf" similar to other shooting suspects who were not connected to domestic terrorist groups or other organized groups, according to ABC News contributor Donald Mihalek, a former senior official with the United States Secret Service.

Mangione was intelligent – a high school valedictorian who earned an Ivy League master's degree. However, investigators say he appeared to have deep-rooted anger, according to Mihalek.

"They will take on the identity of a warrior," Clancy said of the mindset of some lone actors. "They say, 'I'm going to do what society wants to do and what state actors can't do.'"

This mentality is far more dangerous in the aftermath of Thompson's murder, warned Clancy and other experts with whom ABC News spoke.

John Cohen, an ABC News contributor and former Department of Homeland Security (DHS) official, said that one of the biggest red flags in his assessment was what authorities have described as the suspect's alleged withdrawal from society in the months before the incident.

Mangione's family and friends said they lost contact with him earlier in the year, according to authorities. His mother filed a missing persons report in November with the San Francisco Police Department, seeking information on her son's whereabouts, two law enforcement sources told ABC News.

"We often hear they aren't on the radar screen," Cohen said of suspects in similar shootings. "The thing is, they are on the radar screens – law enforcement and the public aren't looking at the right radar screen."

Fuel for a shared anger

The Thompson shooting stands out from other high-profile assassinations, Clancy said, in that a single person was allegedly targeted because of the shooter's alleged anger toward an industry that authorities have said the victim symbolized to Mangione.

The public's fascination with Mangione has grown. A defense fund established in his name collected over $100,000 donations within days of his arrest, with the total nearing $190,000 as of Monday. Dozens of supporters gathered outside of the Manhattan court on Monday where Mangione pleaded not guilty state charges, many of them holding what appeared to be homemade signs that bore messages of support for Mangione and messages critical of the health care industry.

Cohen said that law enforcement had already been on high alert prior to Thompson's murder due to the increased violent online rhetoric over a wide variety of topics such as politics, men's rights, race and income inequality.

"We have a growing number of people who believe that violence is the only way to express their beliefs," Cohen told ABC News. "The reaction is not unexpected. An increasing number in our society are mistrustful of government, businesses and other institutions. They believe they are the victims of inappropriate behavior."

Cohen said it is not out of the question that other lone individuals would want to replicate Thompson's murder and subsequently may feel validated by those who share their stated beliefs – a scenario that is one of the biggest challenges facing law enforcement.

"Law enforcement is pretty good at detecting and stopping threats by groups, whether they be a terrorist group or domestic violence extremist group. What's more difficult is an individual with underlying issues that connect with an underlying cause and independently makes a decision to carry out an attack," he said.

Mihalek said the problem is compounded by online discourse, which can add more vitriol to people's frustrations.

"The dark corners of the internet have become a tool for people who have negative mindsets that support their negative mindset," he said. "The internet can support or embolden people, because of the information put on the internet – often false information."

Clancy added that the positive attention directed toward Mangione's physical appearance, the media coverage during the manhunt and when he was apprehended, and his outburst during an extradition hearing in Pennsylvania last week will only fuel the online fascination with the suspect.

"It's hyper-social media. It's instantaneous, within hours and minutes," he said.

"The challenge with law enforcement today is the use of violence to express one's ideological views or sense of disagreement is becoming fully baked in our society," Cohen said.

Recontextualizing a sensational narrative

Experts with whom ABC News spoke said it's possible to address the issue of potential copycats before others take direct inspiration from Thompson's murder. The first step, Mihalek said, is for prosecutors and law enforcement to stress that killings and shootings are immoral and detrimental to society.

While there may be some who may feel that Thompson's killing was justified because they believe they were hurt by the health insurance industry, the reality is that a person was murdered and others could have been injured or killed in the process, according to Mihalek.

"It's hard to fight because of the celebrity thing. The only way is to point out the facts and keep the eye on the ball," Mihalek said. "He allegedly committed a cold-blooded murder in Manhattan in the middle of the day."

Elected officials, law enforcement and other leaders have publicly condemned Thompson's murder and pushed for a thorough prosecution of his alleged shooter.

Clancy said Mangione's trial, particularly if it's lengthy, could create a repeating glamorization cycle for as long as the trial goes on. He also noted that prosecutors who have won convictions against school shooters and others in the past have often been successful in stripping the allure from a suspect during their trials.

"Failure notoriety is something we can increase," he said.

Addressing underlying anger

Overall, what needs to be addressed is the increased anger being expressed in society against corporate entities, especially the health care industry, the experts told ABC News.

Mihalek said that both law enforcement and the general public will need to keep an eye out for anyone who seems in distress and shares angry rhetoric against health care companies and CEOs, and act if they encounter it.

"Concerning behaviors should not be ignored: They need to be reported and addressed. If somebody says something, don't be afraid to be the someone to raise the flag about it," he said.

Clancy reiterated that the grievances felt by many when it comes to the health care industry, or capitalism in general, are rooted in legitimate concerns expressed by a large majority of people. He stressed that sincere, open communication between the public and the people in power, including emphasis on non-violent responses, is the first step to lowering the temperature.

"If you can find you can off-ramp people at the early stage by saying, 'Hey, you know, you're right, the corporations are greedy, and they are too powerful. We should do something, here's what we can do,' then you can lead to long-term solutions," he said.