noun
modus operandi; criminal technique; trick
Refers to the characteristic method or pattern used by a criminal, or more broadly a clever or underhanded way of doing something. Often used in police and news reports.
警察は犯人の手口から同一犯の可能性が高いと見ている。
The police believe it is highly likely the same perpetrator based on the modus operandi.
詐欺の手口は年々巧妙になっている。
Fraud techniques are becoming more sophisticated every year.