EXCLUSIVE: Luigi Mangione's 'Only Option' Is to Prove He Acted 'Emotionally' – As Accused CEO 'Assassin' Lays Out Blueprint for His Defense

Luigi Mangione has revealed his strategy in the face of overwhelming evidence against him in connection with the killing of UnitedHealthcare CEO Brian Thompson.

The alleged assassin's surprise announcement that he plans to use a "psychiatric defense" at his upcoming murder trial may be his best – and only – option, according to a legal expert, RadarOnline.com can report.

At a hearing on Wednesday, June 17, the 28-year-old's lawyers said they plan to prove that he was suffering from "extreme emotional disturbance" before he reportedly gunned down Thompson outside a New York City hotel.

By using a psychiatric defense, Mangione would effectively be admitting he killed the man, but did so because of mitigating circumstances. That could help lessen the charges against him.

"His factual guilt (shooting and killing the CEO) is undisputed," Nora Demleitner, Senior Fellow at the Council on Criminal Justice, exclusively told Radar. "His only option is to mitigate his mental state so that he isn't convicted of the highest level murder -- intentional and premeditated." A psychiatric defense differs from a plea of insanity in that if a jury finds that Mangione was emotionally disturbed at the time of the killing, it could convict him of manslaughter, leading to less time in prison. An insanity conviction would have spared him prison but sent him to a psychiatric facility.

However, mental health professionals say that could be a tough sell.

"On its face, it appears to be a very, very weak case," said Sandip Buch, psychiatrist and owner of group telehealth practice Skypiatrist.com.

"It is very unclear whether he had a qualifying mental illness, but this crime appeared to take planning and execution, which shows capacity, and his actions of planning and escape showed he knew what he was doing was wrong."

Brian C. Stewart, attorney at Parker & McConkie, said proving Mangione "snapped" could be nearly impossible.

"You need an actual psychiatric break, not just being furious at an industry. And his own writings are organized, deliberate, almost calculating," he explained. "Prosecutors are going to read straight from his notebook to argue this was a man thinking clearly, not a man losing it."

That's why defense attorneys fought so hard to try to rule that notebook, along with other pieces of key evidence, inadmissible.

However, Judge Gregory Carro ruled on May 18 that prosecutors can present the handwritten notebook, along with a 3D-printed pistol that was also recovered from Mangione's backpack after his December 2024 arrest in Altoona, Pennsylvania.

The notebook — repeatedly described by prosecutors as a "manifesto" — allegedly included chilling references to wanting to "whack" a health insurance executive and rebel against what was called the "deadly, greed-fueled health insurance cartel."

Mangione is being held at a federal jail in Brooklyn while awaiting two separate trials for the Dec. 4, 2024, killing. He is set to go to trial in the state case on Sept. 8. His federal trial, which involves stalking charges, is set to begin on Oct. 13.

He has pleaded not guilty in both cases and could spend the rest of his life in prison if convicted in either case.

Mangione's next court date in the state trial comes on July 6.