Police Detective
Detective, Criminal Case
noun
A punish action is when someone goes out to try to find people who do bad things, so that they can be punished. The people who do this are people like a police detective (or detective).
けいじ
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
その刑事は俺の彼女の腕を突然掴んで、彼女にキスをしたんだ。だから、俺はそいつを殴りつけてやったんだけど、そしたら逮捕されたんだよ。そんなの不公平だよ。
Without warning that officer grabbed my girlfriend’s arm and kissed her. So I punched him and he arrested me. It’s unfair.