Let's see, what did Itachi do again?
-Formed an alliance with Obito Uchiha, the guy responsible for the Kyubi's attack on Konoha.
-Helped Obito commit genocide by massacring the entire Uchiha clan.
-Worked under and served Danzo, basically a power-hungry dictator.
-Was the reason Sasuke abandoned Konoha in search of greater power.
-Joined a terrorist organization called Akatsuki and actively participated in recruiting members and hunting bijuus.
-Tortured Kakashi and tried to kill him.
-Went after Naruto along with Kisame and tried to capture the Kyubi in Part 1.
But he totally redeemed himself when he beat Kabuto and stopped the Edo Tensei right? Except basically all the Edos except Madara had been sealed by that point, and Madara himself could escape the Edo Tensei jutsu so it didn't even matter or have a lasting effect.
Itachi would definitely deserve the death penalty. He was by no means a good guy even if the manga portrayed him that way. His only interest was looking out for Sasuke, who's not that great of a person either.