I find it kind of interesting that only 5 out of the 16 characters in this game are truly "innocent":
-Makoto
-Kyoko
-Chihiro
-Kiyotaka
-Sakura
Those are the only five characters in the game that didn't do anything that would be considered illegal. If you want to limit it to just killing/attempting to kill someone, then Byakuya is the only person who would be added to the above list:
-Sayaka: Attempted to kill Leon and conspired to pin the blame on Makoto
-Mukuro: Co-conspirator to the entire thing, so even if she didn't directly try to kill anyone she is still responsible for everyone's deaths
-Leon: Murdered Sayaka
-Mondo: Murdered Chihiro
-Hifumi: Murdered Kiyotaka
-Celeste: Conspired the murder of Kiyotaka, put the blame on Yasuhiro, and murdered Hifumi
-Byakuya: Altered the scene of a crime for the lulz; the only one on this list whose "crime" isn't related to killing someone
-Yasuhiro: Attempted to murder Sakura
-Toko: Hosts Genocide Jill, who, in addition to being a serial killer, attempted to murder Sakura; Toko herself is actually innocent, but that doesn't count for this
-Aoi: Attempted to have everybody executed by altering the scene of the crime
-Junko: Co-conspirator of the entire thing, murdered Mukuro, and executed Leon, Mondo, and Celeste