MUNICH — Retired U.S. autoworker John Demjanjuk was convicted of thousands of counts of acting as an accessory to murder at a Nazi death camp and sentenced on Thursday to five years in prison, a groundbreaking verdict that closed one chapter in a decades-long legal battle.

Judges ordered him released pending appeal, on the ground that he did not pose a flight risk.

Demjanjuk was found guilty of 28,060 counts of being an accessory to murder, one for each person who died during the time he was ruled to have been a guard at the Sobibor camp in Nazi-occupied Poland....