Error In Objecto Definition: A mistake by a perpetrator as to the identity of the victim; an error as to the object of his act. Related Terms: Aberratio Ictus, Mens Rea In Droste v The Queen, Justice Dickson of Canada's Supreme Court used these words:"[E]rror in objecto involves a mistake by (a) perpetrator as to the identity of the victim. A gunman aims at and shoots a pedestrian on the street; the assailant thought the pedestrian was X, but in fact he is Y. There is little controversy that this sort of mistake as to the identity of the victim in no way affects the fact that the perpetrator has committed an intentional crime.REFERENCES:Droste v. R., [1984] 1 S.C.R. 208 Categories & Topics: Criminal Law Dictionary Dictionary of Latin Law Terms Find you are constantly looking up definitions? Try our search provider (works in most modern browsers) If you find an error or omission in Duhaime's Legal Dictionary, or if you have legal term suggestion, we'd love to hear from you!