Police are looking into a potential lead that two men accompanied the gunman who killed three people and wounded nine others in a stabbing and shooting spree at a market in Pathum Thani on Wednesday.

Provincial police chief Maj-General Praphan Phanikhom said yesterday it was possible that Kiartipong Meksawat, the slain gunman, was an escort for the two men, who might have been involved in an illegal deal at Thai Market.

Quoting witnesses, he said the three men arrived at the market on a motorcycle which they later parked in a restricted area. Kiartipong began shooting when a policeman asked him for ownership documents as he was trying to collect his motorcycle, which had earlier been impounded by two security guards.

Praphan said that besides the AK-47 murder weapon with three fully loaded magazines, Kiartipong also had a set of skeleton keys on him. Police are also looking into links between the shootout and a recent increase in auto thefts at the market and nearby areas.

Case investigator Lt-Colonel Thitichat Phanniam said police technicians found a large number of files containing information on firearms and explosives downloaded from the Internet in Kiartipong's computer, apart from his own logs containing details of his frequent target practice.

Police are also contacting people whose numbers were stored in the gunman's mobile phone to get more information about him or the men seen with him.

Most of the nine people wounded by Kiartipong, including four police officers, are out of critical condition, except for Rangsan Wangjor, a security guard whom Kiartipong stabbed twice in the chest, and Theerayuth Sriariya, who was shot in the stomach.

Meanwhile, Department of Mental Health director-general Dr Somchai Chakrabhan called on parents and family members not to neglect children or relatives with character profiles similar to that of the gunman.

He said loners like Kiartipong needed to have family members associate closely with them in order to get them out of their own world as well as to keep check on whether they could potentially turn violent.

The psychiatrist said children with aggressive behaviour could be rehabilitated and raised to become normal adults.

Sergeant Issara Maneesaeng, who was shot dead by Kiartipong, will be promoted posthumously to captain and his family will be given financial assistance. The wounded officers will also be promoted.