also: やめけんべんごし
noun
former prosecutor turned defense lawyer
Colloquial term for a lawyer who previously worked as a public prosecutor. Often implies inside knowledge of prosecution tactics.
ヤメ検弁護士は検察のやり方をよく知っている。
A former prosecutor turned lawyer knows well how the prosecution operates.
彼はヤメ検弁護士として刑事事件を多く扱っている。
As a former prosecutor turned defense lawyer, he handles many criminal cases.
Compound of ヤメ (from 辞める 'to quit') + 検 (abbreviation of 検察 'prosecution') + 弁護士 'lawyer'. The exact origin is uncertain, but it likely arose in legal circles as a colloquial label.