Serial Offender

Serial Offender is a memory in Assassin's Creed: Brotherhood.

Ezio comes across a trail of blood leading to the body of a dead girl propped against a wall. A courtesan is crying over her, who explains to Ezio that she was murdered. Ezio tracks down the killer with the help of the local courtesans. Upon finding him, Ezio orders one of his apprentices to assassinate him.

Dialogue
Ezio finds Malfatto and orders his apprentices to assassinate him. Out of habit, Ezio reaches out to close Malfatto's eyes, only to realize Malfatto's face is covered by a mask.
 * Ezio: Who did this?
 * Courtesan: That monster, Malfatto!
 * Ezio: Did you see him?
 * Courtesan: That way! Oh, Mina. I told you not to come out here...
 * Ezio: Requiescat in pace (Rest in peace).

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.