Reverend Nathaniel, supervisor of the city morgue and cleric of the Church of the Eternal Fire, was a man With a vile character - and a stormy past. Before donning the frock he had served for years as the city torturer.
One would be hard pressed to find a more inferior candidate for a pastor than a former hangman - but, as the saying goes, in Novigrad anything is possible.
To say that Geralt caught Nathaniel red-handed would be an ill-considered pun. Nevertheless, the situation in which Geralt found him clearly indicated this was the man behind the recent wave of killings and so the witcher struck him down in a swift act of justice.
Afterwards, however, a new victims body was found and Nathaniels name was cleared - well, of the killings, that is, for nothing could absolve this priest of his countless other sins.