Pennsylvania Gov. Josh Shapiro (D) condemned “deeply disturbing” reactions to the fatal shooting of UnitedHealthcare CEO Brian Thompson last week.

“Some attention in this case, especially online, has been deeply disturbing, as some have looked to celebrate instead of condemning this killer,” Shapiro said during a press conference Monday, referring to some reports on the internet that show a “lack of sympathy.”

“In some dark corners, this killer is being hailed as a hero. Hear me on this: He is no hero,” the governor added.

Shapiro’s comments come as the suspect, 26-year-old Luigi Mangione, was arrested Monday on local charges in Altoona, Pa. He was recognized at a McDonald’s as the suspect from a surveillance photo.

Prosecutors later filed a murder charge against Mangione after law enforcement found a gun, mask and writings that seemingly linked him to the shooting, according to The Associated Press.

Thompson was fatally shot last week in New York City outside the Hilton Hotel in Midtown Manhattan, where UnitedHealth Group was holding its annual investor conference. Police have said the CEO was targeted.

“In America, we do not kill people in cold blood to resolve policy differences or express a viewpoint,” Shapiro said earlier Monday. “I understand people have real frustration with our health care system, and I have worked to address that throughout my career.”

“But I have no tolerance, nor should anyone, for one man using an illegal ghost gun to murder someone because he thinks his opinion matters most,” he continued. “In a civil society, we are all less safe when ideologues engage in vigilante justice.”

The Pennsylvania governor also thanked law enforcement and praised the Keystone State resident and employee of the McDonald’s where Mangione was arrested for speaking up, calling him a “hero.”