He was found guilty four times, and the verdicts were overturned on appeal because...well, you know. The prosecutor had it in for him, etc.
Flowers was a disgruntled employee who had been fired a few days before. There were no eyewitnesses to the killings, and the gun belonged to his uncle. But his uncle had no reason for killing these people, while Flowers was apparently very angry at being fired and did have a motive.
Prosecutor withheld favorable evidence. He should be prosecuted and disbarred.
Sounds like the appeals court is corrupt.