According to a body language specialist, Luigi Mangione exhibited multiple “red flags” during his arrest by Pennsylvania police, following accusations of murdering UnitedHealthcare CEO Brian Thompson in December 2024.

On Tuesday, prosecutors unveiled body camera footage capturing the moment officers approached Mangione at a McDonald’s in Altoona, Pennsylvania, on December 9, 2024. The video reveals how a restaurant employee identified Mangione and informed a colleague, who subsequently contacted the authorities.

Body language expert Susan Constantine shared her insights with Fox News Digital, noting that Mangione’s behavior raised “red flags” when confronted by police at the McDonald’s after being reported as suspicious.

“When questioned, he had this frozen expression—eyes wide, mouth agape—and didn’t deny or inquire further,” Constantine observed. “His silence was telling. Normally, one would express curiosity or defense,” she explained, highlighting these as significant warning signs.

Luigi Mangione interacts with a police officer in Altoona, Pennsylvania. (Manhattan District Attorney’s Office)

Constantine further remarked on Mangione’s choice to “position himself conspicuously in a corner” while wearing a full mask. She suggested that this form of concealment could indicate “dangerous intent,” which she believes Mangione demonstrated.

“So the fact that he was hiding in the back, that’s one pin, right? Then he’s got the concealment of the clothing. He’s got his little hat down over his eyebrows, then he’s got the mask on and he’s looking down, right? So he’s trying to remove himself from ever being noticed, and that’s what he was doing,” Constantine said.

She added that Mangione knew it was “game over” when he went to grab the driver’s license to hand to police, and had a “fear response” when approached by the officer.

Luigi Mangione talks with a police officer in Altoona, Pennsylvania. (Manhattan District Attorney’s Office)

“At that point, I knew he knew it was game over just because of his body language of being more in a low confidence. You know, his shoulders are kind of pulled in, he’s kind of huddled together. He’s not leaning out and just, you know, going on his computer just doing work. There were so many signals,” Constantine said. “All of those things led to this is an anomaly compared to everybody else that was in that restaurant. That’s what it is. It’s an anomaly.”

The McDonald’s employee who made the initial 911 call identified Mangione as the suspect in Thompson’s death, according to a transcript of the call.

WATCH: Police confront Luigi Mangione at Pennsylvania McDonald’s

“I’m a manager at Plank Road McDonald’s out here on the boulevard,” a McDonald’s manager told the 911 dispatcher. “And I have a customer here, that some other customers were suspicious of, that he looks like the CEO shooter from New York.”

Altoona Police Officer Christy Wasser testified in court on Monday that she found a magazine with bullets wrapped in wet underwear that was inside Mangione’s backpack.

Luigi Mangione allegedly killed UnitedHealthcare CEO Brian Thompson. (AP Photo/UnitedHealth Group via AP)

“There was another magazine hidden in his underwear,” Wasser can be heard saying.

Mangione faces numerous state and federal charges, including the possibility of the death penalty being handed down.