Luigi Mangione, 27, accused of fatally shooting United Healthcare CEO Brian Thompson in Manhattan on December 4, 2024, is set to appear in court Monday as his attorneys seek to suppress diary entries and other evidence in his state murder case.

Mangione was arrested in Pennsylvania after a multi-day manhunt, with police seizing items from his backpack that prosecutors say tie him to the killing.

His defense argues the search was illegal and that certain evidence, including writings labeled a “manifesto,” could unfairly prejudice a jury.

The state hearing is expected to last several days, with both sides calling witnesses, while a related federal death penalty case is scheduled for January 9, CNN has reported.

Mangione has pleaded not guilty to all charges; earlier, two terrorism-related murder charges in the state case were dismissed.