Condemned Criminal
Death Row Convict
noun
Remember how you learned that 死刑 means "death penalty?" Well a criminal who has been sentenced to it is a condemned criminal or a death row convict. They're condemned to death.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
死刑囚はこの階段を登って死刑台へと向かうんだ。
Condemned criminals climbed these stairs and faced the gallows.
そもそも、この問題を起こしたのは、あの死刑囚だ。
It was that death row convict who caused the problem in the first place.
その弁護士は、死刑囚にとって有利な情報ばかりを並べた。
The lawyer laid out all the information that was favorable to the condemned criminal.