An initial forensic probe has suggested that the gun used by attackers to murder eight members of a family in Krabi could have belonged to the deceased head of the family, police sources say.
Police believe the attackers may have used the gun of Worayut Sanglang, 46, as a ruse to lead them into believing the massacre was a murder-suicide, said the sources.
However, not all the people in Worayut's house were killed and one was able to tell police what really happened that day.
In the attack that took place on Monday, three other family members -- a 30-year old woman and two girls aged 13 and 2 -- were shot and injured by a group of eight men wearing army camouflage outfits. The 30-year old woman only sustained a bullet graze to her ear, which caused her to faint, leading the gunmen to believe she was dead.
During police questioning, the woman said she could remember the faces of four of the attackers. Police have placed her under witness protection.
The dead comprised three male victims and five female victims. Three were girls aged four, 11 and 13.
National police chief Pol Gen Chakthip Chaijinda said he went to Krabi's Ao Luk district to meet investigators involved in the case on Tuesday night.
He said while investigators believe a single gun was used in the attack, forensic tests are needed before any conclusions are reached.
He said police have yet to rule out any motives for the massacre and are collecting as much evidence as possible to solve the case.
According to an investigation team source, investigators are focusing on a conflict between Worayut and an influential stone mill operator.
The source said Worayut had received tens of millions of baht from the mill operator to help pave the way for a new stone mill concession and to quell opposition from local residents.
But the operator failed to win the concession and this money may not have been returned, which may have been the motive for the attack, the source said, adding that the stone mill operator has close ties to some influential local politicians.
Another possible motive was Worayut's dispute with the president of a tambon administration organisation in Ao Luk district over a land plot.
Forensic experts say it appears just one gun was used in all eight murders, plus the attempt to kill a ninth person, who survived as a witness.
Manas Chubut, president of Ban Klang tambon administration organisation in Ao Luk district who pursued legal action against Worayut for alleged dereliction of duty in connection with a land encroachment case involving close to 100 rai of land, on Wednesday denied involvement in the massacre of Worayut and his family.
"Conflicts sometimes happen when people work together. But they aren't serious enough to make someone kill someone else. Such brutal and cold-blooded murders have never happened in Krabi before," he said.
Worayut was also involved in a dispute with villagers found encroaching on public land. He had filed suit with a court for an eviction order, said the source.
Also being treated as a possible motive behind the murders is a conflict between Worayut and a drug trafficking gang, said the same source.
Police also said Worayut had been romantically involved with a 39-year-old millionairess in Sing Buri's In Buri district who bought a house and a car for Worayut, said the source.
A team has been sent to the woman's home in Sing Buri to question her, said the source.
Pol Maj Gen Thawatchai Mekprasertsuk, chief of the Office of Police Forensic Science, said an examination of some items of evidence collected from the crime scene on Tuesday pointed to the fact that one .38-calibre revolver owned by Worayut was used to shoot the 11 family members.
He said nine spent bullet casings were found at the scene and they will be compared to the bullets left in the corpses of the victims and retrieved for analysis to confirm the theory that Worayut's own gun was used in the attack.
DNA samples and fingerprints were also collected from the gun found at the scene, he said.
The source said the Crime Suppression Division team investigating the Ao Luk massacre was particularly interested in the stone mill conflict theory.
Witnesses told investigators the attackers had claimed before entering Worayut's home that they were law enforcement officers who had come to search the house following a tip-off there were illicit drugs stashed there, said the source.
The attackers, who arrived in a black Toyota Fortuner with a Songkhla licence plate and a white Toyota Yaris, showed a document they claimed was a court subpoena to villagers when they stopped to ask where Worayut's house was, said the source.