Ezio Auditore comes across a trail of blood, which leads to the body of a dead girl propped against a wall and a crying girl greiving over the body. The crying courtesan tells Ezio that she was murdered by a man named Malfatto. With the healp of the local courtesans, Ezio tracks down the killer and orders one of his apprentices to assassinate him.
Courtesan: That way! Oh, Mina. I told you not to come out here...
Ezio finds Malfatto and orders his apprentices to assassinate him.
Ezio: Requiescat in pace (Rest in peace).
Out of habit, Ezio reaches out to close Malfatto's eyes, only to realize Malfatto's face is covered by a mask.
Outcome
Following the directions of several courtesans throughout the streets, Ezio manages to catch up with Malfatto, and direct one of his apprentices to assassinate him.
Trivia
To achieve 100% synchronization, Malfatto must be killed by an Assassin apprentice.
Even if the apprentices are used to assassinate Malfatto, the cutscene will still show Ezio in the Memory Corridor.
If Ezio skips the final courtesan checkpoint, he can walk up and kill Malfatto with the hidden blade and still achieve 100% synchronization.