New court filings reveal diary entries written by Luigi Mangione, the Ivy League graduate who's charged with the shooting and killing of the CEO of United Healthcare outside a busy Manhattan hotel.

Mangione had a notebook in which he vented about his frustrations with the health insurance industry and his intent to carry out an attack.

The entries also shed light on Mangione's focus on the court of public opinion.

The diary has become central to the state case against Mangione, which charges him with first-degree murder and murder as an act of terrorism, among other offenses. Prosecutors have quoted from the diary to emphasize the alleged premeditated nature of the crimes, saying the notes “convey one clear message: that the murder of Brian Thompson was intended to bring about revolutionary change to the healthcare industry.”

Attorneys for Mangione also want the journal and other evidence barred from the federal case.

The federal case charges Mangione with murder using a firearm, firearms offenses and stalking.

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Mangione has pleaded not guilty to charges. He faces a possible death sentence in the federal case.

Neither the state nor federal cases have trial dates set yet. Mangione is scheduled to next appear in court in the state case on June 26 and in the federal case on December 5.