They Shot the Sun 1982 on netflix

After being released from prison, both Lee Jong-Bae and Moon Do-Seok, who served imprisonment at the same prison, plan to commit crime with carbine rifle having no butt plate. They succeed in the first crime, but kill a person so that Moon regrets his wrong doings. But, Lee commits the second crime to hurt persons. Lee’s wife advises Lee to deliver himself to the police, but Lee neglects her advice.