Six police officers have been sacked from the police force over their alleged involvement in the shooting at a dinner party at a house in Nakhon Pathom on Wednesday night.
In the incident, Pol Maj Siwakorn Saibua was killed and Pol Lt Col Wasin Pandee was injured.
Four of the six officers sacked are from highway police station 1.
The other two sacked officers are an investigator at Krathum Baen police station in Samut Sakhon province and a traffic police officer at Muang police station in Nakhon Pathom.
The six officers are accused of destroying evidence of the crime and helping the suspected gunman and the kamnan, Praween Chankhlai, to escape. The suspected gunman, Thananchai Manmak, was later killed in a gunfight with police in Kanchanaburi province while Mr Praween surrendered to police.
All six officers are facing a serious disciplinary investigation.
A Corrections Department official has also been sacked and is facing an investigation for alleged involvement in the shooting incident.