Lawyers for alleged assassin Luigi Mangione have accused the Manhattan District Attorney’s Office of serious misconduct, a revelation that could significantly impact his murder trial.

Mangione, aged 27, is charged with terrorism-related murder in New York following the shooting of 50-year-old United Healthcare CEO Brian Thompson last December.

Mangione has entered a plea of not guilty and has been detained at the Metropolitan Detention Center in Brooklyn for several months as his legal team and New York City prosecutors ready for trial.

But Mangione’s defense attorneys are now accusing the Manhattan District Attorney’s Office of creating a ‘fraudulent’ subpoena to obtain his confidential medical information from the health insurance giant Aetna.

They allege that the DA’s Office subpoenaed Aetna without a court order – and received more than 100 pages of ‘confidential, private, protected documents’ with information about Mangione’s medical diagnoses and complaints he made to medical providers.

‘At a minimum, the District Attorney has admittedly violated Mr. Mangione’s rights under [the Health Insurance Portability and Accountability Act] and has obtained access to confidential privileged information,’ attorney Karen Friedman Agnifilo writes in the filing submitted to the New York State Supreme Court on Thursday.

‘However, the situation is far worst than this,’ she continued in the court documents obtained by DailyMail.com, saying the subpoena was ‘false and fraudulent.’

She then went on to ask Judge Gregory Carro to ‘impose an appropriate sanction after conducting a full evidentiary hearing to uncover the extent and nature of the significant privilege and HIPAA violations.’

These include the ‘dismissal of all charges,’ sanctions precluding prosecutors from accessing the documents ‘and/or recusing any member of the District Attorney’s staff … from further involvement in this case.’

According to the court documents, Assistant District Attorney Joel Seidemann drafted a subpoena to Aetna on May 14, telling the insurance company that prosecutors were seeking information about Mangione’s account and how long he had been a member.

The subpoena allegedly told Aetna that the documents were needed for a court date of May 23, 2025 – and if the insurance company did not provide related to the request by that date it could be found in contempt of court.

In such a case, Aetna would be liable to a fine of $1,000 and its officers could face one year in prison, the subpoena reportedly warned.

Agnifilo argues that these documents were never warranted in Mangione’s trial ‘as the People have maintained that this is a straightforward murder case.’

She also claims that ‘rather than having Aetna give the documents to the Court, as required by the already fraudulent subpoena, the District Attorney told Aetna to provide the documents directly to the District Attorney.

Doing so, Agnifilo said, ‘intentionally’ excluded the Court from the subpoena process and ensured that prosecutors would ‘secure these confidential medical records without either the court of Mr. Mangione’s counsel knowing or being able to object.’ 

The defense attorney went on to deny that the prosecutors did not know they had received confidential medical information,  describing how each of the files sent to the Manhattan District Attorney’s Office included in ‘large type bold letters “Request for Protected Health Information.”‘

The cover letter from Aetna also stated that the files were provided by the HIPAA Member Rights Teams and advised that the materials were to be kept confidential. 

‘It would be impossible for anyone to view a single page of these records and not immediately see they were private, confidential records within the scope of HIPAA,’ Agnifilo writes.

‘Yet the District Attorney’s Office placed them into a discovery file and reviewed them,’ she said, alleging that prosecutors even admitted to reviewing the documents but not doing so ‘in their entirety.’

‘We need sworn testimony to determine precisely what confidential medical files were reviewed, who reviewed them and when this review was conducted,’ the attorney argued.

‘We also need the computer forensic information of when these files were opened, by whom and for how long.’

The filing concludes by claiming that Assistant District Attorney Zachary Kaplan spoke with a representative from Aetna on June 16, when he was informed that the insurance company ‘mistakenly provided the defendant’s “entire designated record set.”‘

‘Rater than immediately alerting the Court and counsel, the District Attorney’s Office sat on this information for another eight days, before disclosing that it was in possession of over a hundred pages of admittedly confidential, privileged medical information.’

In a statement to DailyMail.com, the Manhattan District Attorney’s Office said it will file its own response in court papers.

‘As defense counsel knows, the People requested very limited information from Aetna, and Aetna sent us additional materials in error,’ the office said. 

‘We deleted the materials as soon as we became aware of them and brought it to defense and the court’s attention.’

Prosecutors have claimed Mangione – the heir to a Maryland property fortune – mused about his intent to ‘wack’ an insurance executive in a notebook and wrote about rebelling against ‘the deadly, greed fueled health insurance cartel.

The DA’s office quoted extensively from the notebook, highlighting his alleged praise for the Unabomber Ted Kaczynski as they fought to uphold his state charges. 

They also cited a confession they say he penned ‘to the feds,’ in which he wrote that ‘it had to be done.’

Manhattan District Attorney Alvin Bragg even called the ambush ‘a killing that was intended to evoke terror.’ 

But Mangione’s attorneys have since been fighting to get the charges in New York dropped, arguing that they amount to double jeopardy, as the 27-year-old also faces a federal death penalty prosecution.

If that fails, they are looking to have his terrorism charges dropped and prosecutors barred from using evidence collected at his arrest in December – including a 9mm handgun, ammunition inscribed with the words ‘delay, deny, and depose’ and the alleged manifesto.

The defense and prosecutors are now scheduled to discuss any outstanding issues on September 16, according to Thursday’s court filing. 

In the meantime, Mangione is being fiercely backed by a slew of fans who have praised him for his alleged actions and started a GiveSendGo page to raise money for his legal defense. 

Some have even made art depicting him as a saint, saying he is a hero who has taken a stand against America’s broken healthcare system. 

DailyMail.com has reached out to the New York State Supreme Court and Aetna for comment.