expression
in the name of justice
Fixed phrase used to justify actions as morally right or legally sanctioned. Often carries a rhetorical or dramatic tone.
彼らは正義の名において戦うと宣言した。
They declared they would fight in the name of justice.
正義の名において、この悪を裁く。
In the name of justice, I shall judge this evil.
General pattern meaning 'in the name of'; 正義の名において is a specific fixed phrase using this construction.
A set phrase combining 正義 (justice) with the formal pattern 〜の名において (in the name of ~). The kanji 於 is an older spelling for the particle おいて, now usually written in kana.