The 99th Assassin of the Rising Dawn is always the youngest and most inexperienced, which is why they alone bear another duty: that of Harbinger. In the spirit of whatever passes for fair play among the Infernal Powers that Be, the 99th Assassin notifies the target of their fate before attempting to serve it.
The current 99th Assassin is Rerus, an eager recruit who sees himself rapidly climbing the ranks despite the fact that it is almost literally impossible for him to do so. As he has limited experience and even more limited funds, his preferred mode of assassination is to incapacitate the target and then place them in an almost assuredly deadly situation to make it appear like a suicide. There’s no reason for this–the Infernum truly does not care if they are implicated or not–but like many of his brethren in the 99th-90th Assassins, it’s felt that this is a classier way to go, and one that generally makes it more likely that the assassin will not face any significant opposition.