Prosecutors in the Luigi Mangione murder trial just entered a bunch of evidence into court … including photos of the gun they say Luigi used to whack UnitedHealthcare CEO Brian Thompson.

The photos are included in new legal docs obtained by TMZ … they show a handgun, bullets and a magazine. Cops say they found the gun and the loaded magazine in Luigi’s bag when he was arrested.

Police previously released photos of the gun last December around the time of Luigi’s arrest … but these are clearer photos from different angles … in other words, it’s the best look yet at the gun Luigi allegedly used to kill Thompson.

Luigi’s court hearing this month have been pretty juicy … prosecutors resurfaced video from the shooting and released the 911 call that led to Luigi’s arrest at a Pennsylvania McDonald’s … plus, we finally saw the body cam footage from the arrest.