Diary entries written by Luigi Mangione reveal the now 27-year-old’s detailed thinking ahead of the alleged killing of UnitedHealthcare CEO Brian Thompson last year, a new court filing shows.

His defense lawyer, Karen Agnifilo Friedman, requested that the top charge be dropped because, she said, it should not be applied to the death of a single person. The Manhattan District Attorney filed an 82-page brief opposing Luigi Mangione's effort to drop his terrorism charges.

Manhattan prosecutors said of Luigi Mangione’s handwritten diary entries, “If ever there were an open-and-shut case pointing to defendant’s guilt, this case is that case.”