The Juvenile Court has acquitted two youths of carrying out an arson attack on CentralWorld and the Zen department store during the 2010 riots.
Their lawyer, Chokechai Angkaew, said the court acquitted them for lack of evidence.
Prosecutors filed the case on Sept 7, 2010 against the young men, then aged 16 and 17, accusing them of setting fire to CentralWorld on May 19 of that year during the military crackdown on red-shirt protesters.
"The arson charge was added afterward," Mr Chokechai said. "Pathumwan police had laid only theft charges during their arrest. No arson materials were found."
Prosecutors alleged the pair committed the crime together with two other men identified as Saichon Phaebua and Pinij Channarong, who are being tried on the arson charge in a separate court.
Warrants have been issued for another five suspects.
The two young men were also acquitted in October of the theft charge, along with seven other adults.
The fire and thefts caused damage of more than 8 billion baht.
One youth said after the ruling he was glad to see justice was done but would like authorities to be more careful before filing charges against innocent people.
"Our futures have been shattered and we've been stigmatised as arsonists, which is untrue," he said.
The other juvenile defendant said he would not be happy until the prosecutor decides not to appeal against the theft and arson rulings. The prosecutor has sought an extension of the appeal deadline.
The youngsters said they wanted to lead normal lives with job and education possibilities. "It's been quite difficult and we've been sort of begging [for help] throughout these years," they said.
CentralWorld shopping centre was set on fire after leaders of the red-shirt protest surrendered to police on May 19, 2010.