atone for a crime by doing good deeds
Atone for one's contribution.
He was one of the kidnappers, but because of his nature, he helped the police to rescue the hostages, and then he was able to reduce his sentence. postscript: riddle: idiom story: related idioms
atone for a crime by doing good deeds
a settled practice is hard to reform - jī xí nán gǎi
hold one 's life on a precarious tenure - mìng zài dàn xī