Files retrieved from a CCTV server previously installed at the house of tambon Takong chief Praween Chankhlai in Nakhon Pathom show individuals present at a dinner party on Sept 6, which resulted in the death of a police officer, have given conflicting accounts.
Pol Maj Sivakorn Saibua, a highway police officer, was shot dead, while Pol Lt Col Wasin Pandee, another highway police officer, sustained injuries. The gunman, Thananchai Manmak, was subsequently killed in a gunfight with the police in Kanchanaburi province.
Pol Gen Surachate Hakparn, deputy national police chief, on Thursday said there were 15 security cameras installed at Mr Praween's house.
After the shooting, two CCTV servers were removed and dumped into a canal behind a temple in tambon Takong in an apparent attempt to destroy evidence, he said.
Pol Gen Surachate said the servers were retrieved and forensic police managed to salvage files related to 13 security cameras. The recovered CCTV footage provided clear audio and video, enabling law enforcement agents to identify individuals present at the scene and their actions both before and after the shooting, he said.
Files related to two of the security cameras were in the process of being salvaged and they were expected to be available for review yesterday, he said.
He said police believed there may have been a plot to commit the crime as two video cameras were unplugged moments before Thananchai shot Pol Maj Sivakorn.
"They knew that [Thananchai] would shoot Pol Maj Sivakorn, so they pulled the plug on the two cameras," he said.
Pol Gen Surachate said more than 56 individuals, including police and civilians, were at the party. Some were arrested and charged over suspected links to the crime, he said, adding they were interrogated.
However, compared to what was seen in the footage, those who were interrogated were found to have given contradictory statements, he said. Therefore, another round of interrogation is to be conducted, he added.
The footage indicates that nearly all police and civilians who were at the party were armed and after the first shot by the gunman, no one tried to intervene, he said.
He said people who were present at the scene can be categorised into three groups: those who took the two police officers to hospital, those who fled the scene and those who remained.
Pol Gen Surachate also confirmed the gunman was indeed Thananchai.
Whether or not Thananchai was ordered by Mr Praween to commit the crime may be made clear after the files from the two video cameras are salvaged and examined.
One of the servers found in the canal was still being salvaged by forensic police, he said.