The Metropolitan Police Bureau has yet to verify if the place where a police officer was shot dead on Monday night was an illegal casino, the bureau chief said.
Pol Lt Gen Pakapong Pongpetra, commissioner of the bureau, said on Wednesday that police were conducting an in-depth investigation into the crime.
“If there is enough evidence to prove that the place was a gambling den, decisive action will be taken,” he said.
The Bangkok police chief referred to the four-storey building off Rama III Road in Yannawa district where Pol Maj Watthaset Samniangprasert, 32, of Samae Dam station and three others were shot dead late Monday night.
It was alleged that the location was functioning as an illegal casino. Earlier the Bangkok police chief said the dead police inspector had not been on official duty there, and it was likely that he had a personal conflict.
In response to reports that people had tried to remove evidence -- including a surveillance camera system -- from the premises, Pol Lt Gen Pakapong said local police arrived at the scene about 30 minutes after being informed of the crime and surveillance cameras had been removed before officers arrived.
He said his bureau was also investigating if local police bad been lax in their duty to prevent illicit business in the area under their jurisdiction.
The three other dead were identified as Peeraya Noomlamul, 44, Thaworn Seesod, 51, and Cambodian woman Mao Salaepao, 29.
It was earlier reported that after sustaining losses, a gambler had claimed he was cheated and was trying to demand a refund. He opened fire at people in the building before being shot dead, reports said. Pol Lt Gen Pakapong said police were trying to identify a gunman at large.
There was evidence that dozens of surveillance cameras had been removed from their stands, along with connecting cables.
Reports also said a blood-stained baccarat table seen just after the shooting on Tuesday had disappeared from the vicinity by Wednesday.
According to a report on TV Channel 3 on Wednesday, the slain police officer owed a gambling debt to the man who killed him. Stray bullets hit and killed two women. The shooter was then shot dead by a casino employee.
Former MP Chuwit Kamolvisit told Spring News the gambling den had been operating for over 20 years and was run by a man known as "Hia Tee".
He said he had information from an insider that the dead police major was a regular gambler and owed money to the gunman. The two men had been arguing about the debt before the shooting began.