Ryan Ferguson walked out a free man from the Boone County jail.
His release comes hours after the Missouri Attorney General said he will not seek a retrial on the murder and robbery charges that put him in prison.
In 2004, Ferguson was convicted of killing Columbia Sports Tribune sports editor Kent Heitholt on Halloween night 2001.
Last week, the Western District Court of Appeals overturned Ferguson's murder and robbery convictions.
The appeals panel said the prosecutor's office had withheld evidence from defense attorneys and that Ferguson did not receive a fair trial.