The Irish magistrate who interrogates Victor Frankenstein is Mr. Kirwin.
Victor encounters Mr. Kirwin in Ireland after the Creature’s violence leads to the death of Henry Clerval. Local authorities discover Victor near the scene and initially suspect him of the murder. Kirwin, the magistrate responsible for the inquiry, questions Victor and arranges for him to be detained while the evidence is examined.
Victor is so physically and mentally ill that he cannot properly defend himself. He spends time in prison and later suffers a severe fever. Kirwin nevertheless behaves with more humanity than a simple stock official: he obtains medical care, communicates with Victor’s father, Alphonse, and helps ensure that Victor receives support during his recovery.
Readers sometimes confuse Kirwin with Victor’s university professors, M. Waldman and M. Krempe, or with the De Lacey family. Those figures belong to different parts of the novel. Kirwin appears during the Irish episode, one of the stages in Victor’s increasingly international flight from the Creature. His investigation also emphasizes how Victor’s private scientific crime has become a public legal matter.