The Appeal Court has overturned the conviction and sentencing of Vivat Yodprasit, better known as the "popcorn gunman" who opposed the aborted February 2014 general election.
The court gave him the benefit of the doubt, ruling there was insufficient proof to justify his conviction by the lower court. However, he remains in prison pending a prosecution appeal to the Supreme Court.
In its ruling read out on Tuesday morning, the court found that none of the several prosecution witnesses was able to assert they had witnessed the defendant's alleged criminal acts.
The police photos presented by the prosecution of a hooded man wearing a black outfit and those of Vivat were all taken by and published by the media. That was insufficient proof that the defendant really was the gunman seen firing shots into the crowd, the court said.
The judge therefore gave the defendant the benefit of the doubt.
The court, however, ordered that the defendant be further detained while the prosecution files an appeal with the Supreme Court.
The Criminal Court on March 3 last year sentenced Vivat, aged 25, to a total of 37 years and 4 months in prison.
He was charged with murder and illegal possession of an assault rifle and ammunition used in a deadly clash between supporters and opponents of the general election, three months before the May 2014 military coup.
The lower court's sentence was reduced from the original life imprisonment because of his alleged confession during police interrogation.
Throughout his trial, he denied any wrongdoing.
Vivat was given the sobriquet the "popcorn gunman" because media photographs at time showed a man wearing a mask and concealing an assault rifle inside a popcorn sack firing several shots during a battle between supporters and opponents of then-prime minister Yingluck Shinawatra at Laksi intersection on Feb 1, 2014.
Four people were hit by bullets. One, bystander A-Kaew Sae Liew, died seven months later.
Vivat was a member of the anti-election camp led by Phra Buddha Isara that was trying to prevent officials gaining access to Laksi district venues to prepare for the Feb 2 poll, according to the lower court's ruling.
The anti-election group, joined by allies from a Lat Phrao rally site, moved along Chaeng Watthana Road towards IT Mall, the ruling said.