Quote from the link:
Taweepong said he then went and filed a complaint against this policeman at Lampang city police station but the investigators did not appear to be interested in the firing of shots at them.
He later found out that the policeman was indeed an officer of the Narcotics Suppression Bureau Lampang branch as he had contacted him to let go of the case in return for 100,000 baht payment.
As a group of men who appeared to be policemen had begun walking around near their house in a threatening manner which made his mother scared he decided to come and file a complaint against the policeman at the Central Investigation Bureau.