yuán​xiōng

culprit

元凶 yuán​xiōng
culprit noun
the primary person or cause responsible for a crime, evil act, or disaster

The police have finally caught the culprit behind this massive explosion.

Frequency

Movie subtitles
1.43 per million appears in 1% of films
Written text
1.34 per million

Sources

Definitions
CC-CEDICT