Cui bono? (/ /), literally "to whom is it a benefit?", is a Latin phrase related to the identification of crime suspects, expressing a utilitarian view that the perpetrator of a crime may be found among those who have something to gain, chiefly with an eye toward financial gain. The party which benefits may not always be obvious or may have successfully diverted attention to a scapegoat, for example.
L. Cassius ille, quem populus Romanus verissimum et sapientissimum iudicem putabat, identidem in causis quaerere solebat, cui bono fuisset?
The famous Lucius Cassius, whom the Roman people used to regard as a very honest and wise judge, was in the habit of asking, time and again, to whose benefit it be?
|—Cicero: Pro Roscio Amerino, §§ 84, 86|