A judge (a person who presides over court cases); judicial officer (older or formal term; modern Japanese usually uses 裁判官).
その事件は経験のある判事が担当した。
An experienced judge handled that case.
判事の判断は法廷で大きな影響を与えた。
The judge's ruling had a major impact in court.
昔の文献では「判事」という語がよく見られる。
You can often see the word '判事' in older documents.