Luigi Mangione has appeared in court seeking to bar evidence from his state trial over the killing of UnitedHealthcare CEO Brian Thompson.

Among the evidence the 27-year-old Mangione’s lawyers want to prevent the Manhattan District Attorney’s Office from presenting to jurors is a handgun that prosecutors say matches the one used in the Dec. 4, 2024, killing and a handwritten notebook in which they say Mangione described his intent to “wack” a health insurance executive.

Court officials say the hearings could take more than a week, meaning they would extend through Thursday’s anniversary of the attack. Mangione, the Ivy League-educated scion of a wealthy Maryland family, was arrested in Altoona, Pennsylvania, five days after the killing.