NEW YORK (AP) — Six weeks before UnitedHealthcare CEO Brian Thompson was gunned down outside a Manhattan hotel in December, suspect Luigi Mangione mused about rebelling against “the deadly, greed fueled health insurance cartel” and said killing the executive “conveys a greedy bastard that had it coming,” prosecutors revealed Wednesday.

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

Luigi Mangione reportedly mapped out his thought process before allegedly killing UnitedHealthcare CEO Brian Thompson in a journal found on his person during his detainment.