offender; criminal; perpetrator
Dated term, especially used historically for a murderer or the person who committed a crime. In modern contexts, 犯人 or 加害者 is more common.
In Edo-period documents, his name is recorded as the offender.
I heard that the perpetrator had already been caught.
Compound of 下手 (geshu, 'to carry out' or 'to do') and 人 (nin, 'person'). The exact historical derivation is uncertain, but it has been used in legal and historical contexts to refer to a person who committed a crime, especially murder.