Nantasak Poonsook, director-general of the OAG's Administrative Litigation Office, said the officers were very careless in carrying out their investigation and intelligence-gathering and should have had enough information and evidence to know the 21-year-old Chulalongkorn Unviersity law student was not a drug dealer.
Pol Sub-Lt Supot Toket, Pol Snr Sgt Maj Rassami Theptha and Pol Snr Sgt Maj Chamnian Khandaeng were pursuing a drug suspect Saturday when they mistook a Suzuki Swift driven by Apisada Sajjapanroj for the dealer's.
They blocked her car with their unmarked police pickup and the plainclothes officers then surrounded her car without identifying themselves as law enforcement. In fright, the young woman reversed her car and collided with a Mercedes-Benz.
One of the undercover officers then fired several shots at the wheels of Ms Apisada's car. She accelerated and crashed into several more vehicles before coming to a stop. The officers searched her car but found nothing, and fled when her relatives arrived.
Mr Nantasak said the officers should have known by the make of the car, licence plate and Ms Apisada's travel route that she was not the suspect they seeking.
"Honestly speaking, this group of policemen were very sloppy," he said.
Mr Nanatasak said Ms Apisada could sue the three officers for breaching the 1996 Tortious Liability of Officials Act and their superiors and the Royal Thai Police must be held accountable directly.
But the lawsuit cannot be filed against the officers directly according to the act's Section 5, he said. Whether the officers and their commanders will face criminal liability would depend on the findings of the police investigation.
Forensic police on Monday examined Ms Apisada's Swift and found the vehicle's right front tyre had been shot with three bullets, one of which identified as a 9mm bullethead. The right rear tyre was punctured with two bullets. Police also found another bullethead inside the tube.
Police said they would compare the bullets with the gun of Pol Snr Sgt Maj Rassami who said he had fired five shots at the student's car.