
The court cited insufficient evidence and suspicious investigative procedures as grounds for acquittal.
Surachai was charged following a sting operation in connection with the red protests in 2010.
The court said prosecutors failed to provide witnesses to establish the connection between Surachai and the seized weapons and there were no witnesses who saw Surachai carrying the seized weapons. The court said the sting operation appeared doubtful.
Surachai has been detained at the Bangkok Remand Prison without being released on bail.