格殺勿論

格杀勿论
géshāwùlùn
(idiom) to kill on sight (without fear of prosecution)

CEDICT

Use of deadly force authorized; it is permitted to kill (someone) without any legal consequence.

Wiktionary

當場擊殺而不以殺人論罪。

重編國語辭典

擊殺兇惡的人不以殺人論罪

維基詞典

Entry Composition

1 格殺 géshā
  1. (archaic) to strike dead; to kill (by violence)
  2. to strike dead; to kill (by violence)
2 勿論 wùlùn
  1. (literary) to not prosecute
  2. to not prosecute