From: Rabbi Moshe Sofer
To: Unknown recipient
Five witnesses identified a drowned man's body through tevi'as ayin and two physical marks (a scar above the right eye and a crooked nose); the Chasam Sofer rules that the combination constitutes sufficient identification and permits the wife to remarry. He rejects a proposed sfek sfeika argument based on ishtahi, holding the relevant doubt is singular. In an addendum, he concludes that the same evidence establishes the death as a suicide.
Source: Shu"t Chasam Sofer EH I §60