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‘I knew it was him immediately,’ officer who found Luigi Mangione testifies at evidence hearing

By Aaron Katersky, Tonya Simpson and Peter Charalambous, ABC News Dec 2, 2025 | 1:04 PM
Luigi Mangione appears for the second day of a suppression of evidence hearing in the killing of UnitedHealthcare CEO Brian Thompson on December 02, 2025 in New York City. (Michael M. Santiago/Getty Images)

(NEW YORK) — A police officer who responded last Dec. 9 to a McDonald’s where witnesses said they may have spotted the man accused of killing a health care CEO testified Tuesday that he knew right away it was the suspect.

“I knew it was him immediately,” Altoona, Pennsylvania, police officer Joseph Detwiler testified about Luigi Mangione, who is accused of killing United Healthcare CEO Brian Thompson in New York City last year.

Mangione, 27, is in court Tuesday for the second day of a high-stakes hearing in his state criminal case, where his lawyers are fighting to bar prosecutors from using key evidence against him — including the alleged murder weapon and writings that prosecutors say amount to a confession — by arguing it was unlawfully seized when his backpack was searched without a warrant.

The backpack was searched by law enforcement as they arrested Mangione in Pennsylvania, five days after the fatal shooting of Thompson on a sidewalk in midtown Manhattan. Mangione has pleaded not guilty to killing Thompson.

Defense attorneys have alleged that Detwiler violated Mangione’s rights by questioning him for nearly 20 minutes without reading him his Miranda rights. They argue that mistake should justify barring prosecutors from introducing any testimony about the statements Mangione made to police that morning. 

Recollecting the events of Dec. 9, Detwiler testified that he responded sarcastically when he got the dispatch call that a local McDonald’s manager reported a “male who looks like the NYC shooter.” He said he didn’t even turn on his police sirens when he drove to the McDonald’s because he “did not think it was going to be him.” 

“I did not think it was going to be the person they thought it was,” he testified, though he noted his supervisor promised to buy him a “hoagie” if he “got the NYC shooter.” 

“I said consider it done,” Detwiler testified. 

An avid watcher of Fox News, Detwiler testified he saw the images of the murder suspect “a lot” and was familiar with the ongoing coverage of the high-profile assassination. Prosecutor Joel Seidemann walked through each of the photos of the suspect that circulated after the shooting; each time, Detwiler responded in a monotone voice that said he saw the pictures in the same place — Fox News. 

“I saw a lot of Fox News and saw a lot of video and articles on the shooter. I saw the person’s picture many, many times prior to those five days — many times,” he said. 

During Detwiler’s testimony, prosecutors for the first time played his body-camera footage from the morning of Dec. 9. The footage showed Detwiler and his partner casually entering the McDonald’s before turning right to the rear of the restaurant, where they found Mangione sitting at a table. 

“What’s your name?” Detwiler asked in the footage. 

“Mark,” Mangione said.

“Mark what?” Detwiler asked. 

“Mark Rosario,” Mangione said. 

Prosecutors have accused Mangione of showing a fake ID under the name Mark Rosario of New Jersey. Prosecutors displayed a blown-up, poster-sized version of the ID on an easel at the front of the courtroom.

“Someone called and said you were suspicious,” Detwiler said in the video. “Thought you looked like someone.”

Detwiler is heard on the body camera asking Mangione if he was in New York recently.

“I thought he said yes but I wasn’t definitely sure,” Detwiler testified about Mangione’s mumbled response.

“You seem a little nervous. Why are you nervous?” Detwiler is heard saying in the video before frisking Mangione, which the officer told the court he did for his and his partner’s safety to make sure there were no weapons.

When Seidemann asked why Detwiler was concerned for his safety, the officer replied, “I knew up in New York they hadn’t found the firearm.”

 

On the body camera, Detwiler was seen stepping out of the restaurant and calling a supervisor.

“Yes, he’s here. That’s him,” Dewiler is heard saying. “He’s acting real nervous. I’m 100% sure it’s him.”

According to the body camera footage, Mangione told officers he was homeless.

As officers checked with dispatch to confirm Mangione’s identity, Mangione sat at his table to finish his breakfast, according to the footage.

Detwiler said his supervisor instructed him to inform Mangione he was under police investigation and again warn him against using a fake identification. 

After the warning, Mangione told police his real identity and birthday, according to Detwiler and the body camera footage. 

When asked by an officer why he lied about his name, Mangione said in the footage, “That was the ID I had in my wallet.”

After the admission, police officer Stephen Fox began reading Mangione his rights at 9:48 a.m. — 19 minutes after officers first approached him in the McDonald’s, according to body camera footage. The officer noted that Mangione was not in custody at this point.

Two minutes later, Fox began the process of arresting Mangione, asking him to place his hands on the wall as his wrists were handcuffed and zip tied.

Body camera footage played in court showed police rummaging through Mangione’s bulky jacket and other garments. Detwiler recalled on the stand that Mangione was wearing at least three layers of clothing and had “a lot of money” in his wallet. Prosecutors showed a photograph of the wallet positioned with dozens of hundred-dollar bills and foreign currency.

Another officer, Christy Wasser, is seen in the footage searching Mangione’s backpack. Detwiler testified that the search of the backpack began only after Mangione was placed under arrest and was conducted according to Pennsylvania law. 

“We search everyone that’s being arrested, their person and their bags,” Detwiler said.

Prosecutors introduced the Altoona police procedure manual that allows clothing and a bag of a person being placed under arrest to be searched. Detwiler testified he had no knowledge of New York search and seizure laws or when New York law permits a suspect to be questioned.

Prosecutors on the first day of the hearing on Monday played for the first time security camera footage from inside the McDonald’s where Mangione was arrested, the 911 call placed by the store manager who expressed alarm that he “looked like the CEO shooter in New York,” and the minute-to-minute dispatch audio leading to his arrest. 

“There’s a male in the store that looks like the NYC shooter,” a dispatcher said in a recording played in court. 

The crux of Mangione’s argument is that his constitutional rights were violated when Pennsylvania police interrogated him before reading him his rights and searching his backpack without a warrant. 

Defense lawyers allege that officers waited nearly 20 minutes after first approaching Mangione, extensively questioning him about his whereabouts without informing him of his right to remain silent. 

They also allege that officers searched through his backpack — which allegedly contained a handgun, magazine, and his journal — without having a warrant. 

Citing police body camera footage, they argue that officers searched Mangione’s backpack as early as 9:58 a.m. but waited until after 5 p.m. to seek a warrant. They have asked the judge to limit prosecutors from using the evidence because it was the “fruit” of an illegal search. 

Prosecutors argue the arrest and search were conducted lawfully, and that the evidence overwhelmingly proves Mangione’s guilt. 

If defense attorneys succeed in limiting the evidence seized from Mangione’s backpack and statements made during his arrests, they could severely undercut the prosecution’s case against the alleged murderer. 

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